CHAPTER XI.
Collieries of the North of England.—Fire-damp.—The dreadful explosion at Felling Colliery described.—Letters from the Bishop of Bristol to the Author.—A Society is established at Bishop-Wearmouth for preventing accidents in coal mines.—Various projects for ensuring the miner's safety.—The Reverend Dr. Gray, the present Bishop of Bristol, addresses a letter to Sir H. Davy, and invites his attention to the subject.—Sir H. Davy's reply.—Farther correspondence upon the possibility of devising means of security.—Sir H. Davy proposes four different kinds of lamp for the purpose.—The Safe-lamp—The Blowing-lamp—The Piston-lamp—The Charcoal-lamp.—His investigation of the properties of fire-damp leads to the discovery of a new principle of safety.—His views developed in a paper read before the Royal Society on the 9th of November 1815.—The first Safety-lamp. —Safety-tubes superseded by Safety-canals.—Flame Sieves.—Wire-gauze lamp.—The phenomenon of slow Combustion, and its curious application.—The invention of the Safety-lamp claimed by a Mr. Stephenson.—A deputation of Coal-owners wait upon Sir H. Davy, in order to express to him the thanks of the Proprietors for his discovery.—Mr. Buddle announces to Dr. Gray (now Bishop of Bristol) the intention of the Coal trade to present him with a service of plate.—The Resolutions are opposed, and the claims of Stephenson urged, by Mr. W. Brandling.—A dinner is given to Sir Humphry, at which the plate is presented to him.—The President and Council of the Royal Society protest against the claims still urged by Mr. Stephenson's friends.—Mr. Buddle's letter in answer to several queries submitted to him by the Author.—Davy's Researches on Flame.—He receives from the Royal Society the Rumford Medals.—Is created a Baronet.—Some observations on the apathy of the State in rewarding scientific merit.—The Geological Society of Cornwall receives the patronage and support of Sir Humphry.
A few months after the return of Sir Humphry Davy to England, his talents were put in requisition to discover some remedy for an evil which had hitherto defied the skill of the best practical engineers and mechanics of the kingdom, and which continued to scatter misery and death amidst an important and laborious class of our countrymen.
To collect and publish a detailed account of the numerous and awful accidents which have occurred within the last few years, from the explosion of inflammable air, or fire-damp, in the coal mines of the North of England, would present a picture of the most appalling nature. It appears from a statement by Dr. Clanny, in the year 1813,[22] that, in the space of seven years, upwards of three hundred pitmen had been suddenly deprived of their lives, besides a considerable number who had been severely wounded; and that more than three hundred women and children had been left in a state of the greatest distress and poverty; since which period the mines have increased in depth, and until the happy discovery of Davy, the accidents continued to increase in number.
It may well be asked how it can possibly have happened that, in a country so enlightened by science and so distinguished for humanity, an evil of such fearful magnitude, and of such frequent recurrence, should for so long a period have excited but little sympathy, beyond the immediate scene of the catastrophe. It would seem that a certain degree of doubt and mystery, or novelty, is essentially necessary to create that species of dramatic interest by which the passions are excited through the medium of the imagination: it is thus that the philanthropist penetrates unknown regions, in search of objects for his compassion, while he passes unheeded the miserable groups who crowd his threshold; it is thus that the statesman pleads the injuries of the Negro with an eloquence that shakes the thrones of kings, while he bestows not a thought upon the intrepid labourers in his own country, who for a miserable pittance pass their days in the caverns of the earth, to procure for him the means of defying the severity of winter, and of chasing away the gloom of his climate by an artificial sunshine.
That the benefits conferred upon mankind by the labours of Sir H. Davy may be properly appreciated, it is necessary to describe the magnitude of the evil which his genius has removed, as well as the numerous difficulties which opposed his efforts and counteracted his designs.
The great coal field,[23] the scene of those awful accidents which will be hereafter described, extends over a considerable part of the counties of Northumberland and Durham. The whole surface has been calculated at a hundred and eighty square miles, and the number of different beds of coal has been stated to exceed forty; many of which, however, are insignificant in point of dimensions. The two most important are about six feet in thickness, and are distinguished by the names of High main, and Low main, the former being about sixty fathoms above the latter.
From this statement, some idea may be formed of the great extent of the excavations, and of the consequent difficulty of successfully ventilating the mines. In some collieries, they are continued for many miles, forming numerous windings and turnings, along which the pitmen have frequently to walk for forty or fifty minutes, before they arrive at the workings; during which time, as well as when at work, they have no direct communication with the surface of the earth. The most ingenious machinery, however, has been contrived for conducting pure air through every part of the mine, and for even ventilating the old excavations, which are technically called Wastes; and unless some obstruction occur, the plan[24] so far answers, as to furnish wholesome air to the pitmen, and to diminish, although, for reasons to be hereafter stated, it can never wholly prevent, the dangers of fire-damp; the nature of which it will be necessary to consider.
The coal appears to part with a portion of carburetted hydrogen, when newly exposed to the atmosphere; a fact which explains the well-known circumstance of the coal being more inflammable when fresh from the pit, than after long exposure to the air. We are informed by the Rev. Mr. Hodgson, that, on pounding some common Newcastle coal fresh from the mine, in a cask furnished with a small aperture, he found the gas which issued from it to be inflammable; and Davy, on breaking some lumps of coal under water, also ascertained that they gave off inflammable gas. The supposition that the coal strata have been formed under a pressure greater than that of the atmosphere, may furnish a clue to the comprehension of this phenomenon.
On some occasions the pitmen have opened with their picks crevices, or fissures, in the coal or shale, which have emitted as much as seven hundred hogsheads of fire-damp in a minute. These Blowers, as they are technically termed, have been known to continue in a state of activity for many months, or even years together;[25] a phenomenon which clearly shows that the carburetted hydrogen must have existed in the cavities of the strata in a very highly compressed, if not actually in a liquid state, and which, on the diminution of pressure, has resumed its elastic form.
All the sources of carburetted hydrogen would appear to unite in the deep and valuable collieries situated between the great North road and the sea. Their air courses are thirty or forty miles in length; and here, as might be expected, the most tremendous explosions have happened. Old workings, likewise, upon being broken into, have not unfrequently been found filled with this gas, and which, by mingling itself with the common air, has converted the whole atmosphere of the mine into a magazine of fire-damp.
On the approach of a candle, it is in an instant kindled: the expanding fluid drives before it a roaring whirlwind of flaming air, which tears up every thing in its progress, scorching some of the miners to a cinder, and burying others under enormous ruins shaken from the roof; when thundering to the shafts, it converts the mine, as it were, into an enormous piece of artillery, and wastes its fury in a discharge of thick clouds of coal-dust, stones, and timber, together with the limbs and mangled bodies of men and horses.
But this first, though apparently the most appalling, is not the most destructive effect of these subterraneous combustions. All the stoppings and trapdoors of the mine being blown down by the violence of the concussion, and the atmospheric current entirely excluded from the workings, such of the miners as may have survived the discharge are doomed to the more painful and lingering death of suffocation from the after-damp, or stythe, as it is termed, which immediately results from the combustion, and occupies the vacuum necessarily produced by it.
As the phenomena accompanying these explosions are always of the same description, to relate the numerous recorded histories of such accidents would be only to multiply pictures of death and human suffering, without an adequate object: it is, however, essential to the just comprehension of the subject, that the reader should receive at least one well-authenticated account, in all its terrific details; and I have accordingly selected that which was originally drawn up with much accuracy and feeling by the Reverend John Hodgson, and which is prefixed to the funeral sermon preached on the occasion, and subsequently published by that gentleman.
The accident occurred at Felling Colliery, near Sunderland, on the 25th of May, in the year 1812. This mine was considered by the workmen as a model of perfection, both with regard to the purity of its air, and the arrangements of its machinery. The concern was in the highest degree prosperous; and no accident, except a trifling explosion which slightly scorched two or three pitmen, had ever occurred.
Two shifts, or sets of men, were constantly employed, the first of which entered the mine at four, and were relieved at their working posts by the next set at eleven o'clock in the morning; but such was the confidence of the pitmen in the safety of this mine, that the second shift of men were often at their posts before the first set had left them; and such happened to be the case on the following unhappy occasion.
About half past eleven, on the morning of the 25th of May, the neighbouring villages were alarmed by a tremendous explosion. The subterraneous fire broke forth with two heavy discharges from the shaft called the 'John Pit,' which was one hundred and two fathoms deep, and were almost immediately followed by one from that termed the 'William pit,' A slight trembling, as if from an earthquake, was felt for about half a mile around the workings; and the noise of the explosion, though dull, was heard to the distance of three or four miles, and greatly resembled an unsteady fire of infantry.
Immense quantities of dust and small coal accompanied these blasts, and rose high into the air, in the form of an inverted cone. The heaviest part of the ejected matter, such as masses of timber, and fragments of coal, fell near the pit, but the dust, borne away by a strong west wind, fell in a continued shower to the distance of a mile and a half; and in the village of Heworth, it caused a gloom, like that of early twilight, and so covered the roads that the footsteps of passengers were strongly imprinted on them.
As soon as the explosion had been heard, the wives and children of the pitmen rushed to the working pit. Wildness and terror were pictured in every countenance. The crowd thickened from every side, and in a very short period several hundred persons had collected together; and the air resounded with exclamations of despair for the fate of husbands, parents, and children.
The machinery having been rendered useless by the eruption, the rope of the gin was sent down the shaft with all possible expedition. In the absence of horses, a number of men, who seemed to acquire strength as the necessity for it increased, applied their shoulders to the starts, or shafts of the gin, and worked it with astonishing expedition.
By twelve o'clock, thirty-two persons, all that survived this dreadful catastrophe, had been brought to daylight, but of these three boys lived only a few hours. The dead bodies of two boys, miserably scorched and shattered, were also brought up at the same time. Twenty-nine persons, then, were all who were left to relate what they had observed of the appearances and effect of the explosion. One hundred and twenty-one were in the mine when it happened, eighty-seven of whom remained in the workings. Eight persons had fortunately come up a short time before the accident.
Those who had their friends restored, hastened with them from the scene of destruction, and for a while appeared to suffer as much from an excess of joy, as they had a short time before from the depth of despair; while those who were yet in the agony of suspense, filled the air with shrieks and howlings, and ran about wringing their hands and throwing their bodies into the most frantic and extravagant gestures.
As not one of the pitmen had escaped from the mine by the only avenue open to them, the apprehension for their safety momentarily increased, and at a quarter after twelve o'clock, nine persons descended the John pit, with the faint hope that some might still survive.
As the fire-damp would have been instantly ignited by candles, they lighted their way by steel-mills;[26] and knowing that a great number of the miners must have been at the crane when the explosion happened, they at once attempted to reach that spot: their progress, however, was very soon intercepted by the prevalence of choak damp, and the sparks from their steel-mill fell into it like dark drops of blood: deprived therefore of light, and nearly suffocated by the noxious atmosphere, they retraced their steps towards the shaft, but they were shortly stopped by a thick smoke which stood like a wall before them. Here their steel-mills became entirely useless, and the chance of their ever finding any of their companions alive entirely hopeless; to which should also be added the horror arising from the conviction of the mine being on fire, and the probability of a second explosion occurring at the next moment, and of their being buried in the ruins it would occasion.
At two o'clock, five of the intrepid persons who had thus nobly volunteered their assistance, ascended; two were still in the shaft, and the other two remained below, when a second explosion, much less severe, however, than the first, excited amongst the relatives of those entombed in the mine still more frightful expressions of grief and despair. The persons in the shaft experienced but little inconvenience from this fresh eruption, while those below, on hearing the distant growlings, immediately threw themselves flat on their faces, and in this posture, by keeping a firm hold on a strong wooden prop, they felt no other annoyance from the blast than that of having their bodies tossed in various directions, in the manner that a buoy is heaved by the waves of the sea. As soon as the atmospheric current returned down the shaft, they were safely drawn to the light.
As each came up, he was surrounded by a group of anxious enquirers; but not a ray of hope could be elicited; and the second explosion so strongly corroborated their account of the impure state of the mine, that their assertions for the present seemed to obtain credit. This impression, however, was but of short duration,—hope still lingered; they recollected that persons had survived similar accidents, and that, upon opening the mine, they had been found alive after considerable intervals. Three miners, for instance, had been shut up for forty days in a pit near Byker, and during the whole of that period had subsisted on candles and horse-beans. Persons too were not wanting to agitate the minds of the relatives with disbelief in the report of the pitmen who had lately descended to explore the mine. It was suggested to them, that want of courage, or bribery, might have induced them to magnify the danger, and to represent the impossibility of reaching the bodies of the unfortunate sufferers. By this species of wicked industry, the grief of the neighbourhood began to change its gloomy, for an irritable aspect. The proposition to exclude the atmospheric air from the mine, in order to extinguish the fire, was received with the cries of Murder!—and with the determination to oppose such a proceeding by violence.
Many of the widows lingered about the mouth of the pit during the whole of the night with the hope of hearing the cries of a husband or a son.
On Tuesday the 26th, that natural propensity in the human mind to derive gratification from spectacles of horror, was exemplified in a very striking manner. An immense crowd of colliers from various parts, but more especially from the banks of the river Wear, assembled around the pit, and were clamorous in their reproaches of the persons concerned in the management of the mine, accusing them of want of perseverance in their attempts to rescue the unhappy sufferers. Every one had some successful adventure to relate; all were liberal in their professions of readiness to give assistance; but not one was found hardy enough to enter the jaws of the burning cavern.
The leaders of this outcry, however, who had been led into error by an impulse which did honour to their hearts, were soon brought to listen with patience to a relation of all the circumstances of the explosion, and of the reasons for concluding that the mine was then actually on fire, and the persons enclosed in it beyond the hope of recovery. They very candidly allowed, after this explanation, the impracticability of any attempt to reach the bodies of the sufferers, until the fire was extinguished; and they accordingly urged the propriety of excluding from the mine the access of air, as the only means of accomplishing the object. At the same time, the proprietors gave the strongest assurances to the multitude, that if any project could be devised for the recovery of their friends, no cost or labour should be spared in executing it; that, if any person could be found willing to enter the mine, every facility and assistance should be afforded him; but, as they were assured by the most eminent Viewers that the workings were inaccessible, they would not hold out any reward for the attempt,—they would not be accessary to the death of any one, either by persuasion or bribery.
At the clamorous solicitation, however, of the populace, two persons again descended the shaft, and very nearly lost their lives in the attempt. The report of these last adventurers, in a great measure, convinced the people of the impossibility of their friends' survival in so deadly an atmosphere, and reconciled them to the plan of excluding the air. The operation was accordingly commenced, and it proceeded without interruption; but from various accidents, more than a month elapsed before the mine was in a state to admit of examination; and during this interval, numerous were the idle tales which had been circulated throughout the country. Several of the sufferers, it was said, had found their way to the shafts, and been recovered. Their number even had been circumstantially told—how they had subsisted on candles, oats, and beans, and how they had heard the different persons who explored the mine in the hope of rescuing them.
Some conjuror too, it was said, had set his spells and divinations to work, and had penetrated all the secrets of the mine. He had discovered one famishing group receiving drops of water from the roof, another eating their shoes and clothes, and many other similar pictures of horror. These inventions were carefully related to the widows, and they produced the effect of daily harrowing up afresh their sorrows; indeed, it seemed the chief employment of some to indulge in a kind of insane sport with their own and their neighbours' calamity.
The morning of Wednesday the 8th of July having been appointed for exploring the workings, the distress of the neighbourhood was again renewed at an early hour: a great concourse of people assembled; some, out of curiosity, to witness the commencement of an undertaking full of sadness and danger,—some to excite the revenge, or to aggravate the sorrows, of the relatives by calumnies and reproaches, for the sole purpose of mischief; but the greater part came with broken hearts and streaming eyes, in expectation of seeing the mangled corpse of a father, brother, husband, or son.
The shifts of men employed in this doleful and unwholesome work were generally about eight in number. They were four hours in, and eight hours out of the mine; so that each individual wrought two shifts every twenty-four hours.
When the first shift of men came up, a message was dispatched for a number of coffins to be in readiness at the mouth of the pit. Ninety-two had been prepared, and they had to pass by the village of Low Felling, in their way to the mine. As soon as a cart-load of them was seen, the howling of the women, who, hitherto secluded in their dwellings, had now begun to assemble about their doors, came on the breeze in slow fitful gusts, which presaged a scene of the greatest distress and confusion.
The bodies were found under various circumstances: one miner, from his position, must have been sleeping when the explosion happened, and had never opened his eyes. In one spot were found twenty-one bodies in ghastly confusion,—some like mummies, scorched as dry as if they had been baked; one wanted its head, another an arm—the scene was most terrific: the power of the fire was visible upon all, but its effects were very various; while some were almost torn to pieces, there were others who appeared as if they had sunk down overpowered by sleep.
Every family had made arrangements for receiving the dead bodies of their kindred; but Dr. Ramsay having given his opinion, that such a proceeding might spread a putrid fever through the neighbourhood, and the first body when exposed to observation having presented a most horrid and corrupt appearance, the people very properly consented to have each body interred as soon as it was discovered, on condition that the hearse, in its way to the chapel-yard, should pass by the door of the deceased.
From the 8th of July to the 19th of September, the heart-rending scene of mothers and widows examining the putrid bodies of their sons and husbands, for marks by which to identify them, was daily renewed; but very few of them were recognised by any personal mark—they were too much mangled and scorched to retain any of their features: their clothes, tobacco-boxes, and shoes, were therefore the only indications by which they could be identified.
The total loss from this terrible accident was ninety-two pitmen; while forty widows, sixty girls, and twenty-six boys, comprising in all one hundred and twenty six persons, were thrown upon the benevolence of the public.
It was impossible that an event of such awful magnitude should not have deeply affected every humane person resident in the district. Nothing, in short, could exceed the anxiety which was manifested on the occasion; but, most unfortunately, there existed an invincible prejudice against every proposition that could be offered, from a general impression as to the utter hopelessness of any attempt to discover a remedy. A few philosophic individuals, however, did form themselves, as we shall presently learn, into an association for the laudable purpose of inviting the attention of scientific men to the subject, and of obtaining from them any suggestions which might lead to a more secure method of lighting the mines.
To the Reverend Dr. Gray, the present Lord Bishop of Bristol, who, at the period to which I allude, was the Rector of Bishop-Wearmouth, and one of the most zealous and intelligent members of the association, I beg to offer my public acknowledgments and thanks for the several highly interesting communications and letters with which his Lordship has obliged me, and by means of which I have been enabled to present to the scientific world a complete history of those proceedings which have so happily led to a discovery, of which it is not too much to say that it is, at once, the pride of science, the triumph of humanity, and the glory of the age in which we live.
In a letter I had lately the honour of receiving from that learned prelate, his Lordship says, "It was at a time when all relief was deemed hopeless, that Mr. Wilkinson, a barrister in London, and a gentleman distinguished for the humanity of his disposition, suggested the expediency of establishing a society for the purpose of enquiring whether any, and what, methods of security might be adopted for the prevention of those accidents so frequently occurring in the collieries of Northumberland and Durham.
"In consequence of this benevolent suggestion, a society was established at Bishop-Wearmouth, on the 1st of October 1813, by Sir Ralph Milbanke, afterwards Sir Ralph Noel, Dr. Gray, Dr. Pemberton, Mr. Robinson, Mr. Stephenson, and several other gentlemen. It was entitled, 'A Society for preventing Accidents in Coal-Mines;' and it immediately obtained the patronage of the Bishop of Durham, the Duke of Northumberland, and other noblemen and gentlemen.
"A very few days before the first meeting, twenty-seven persons had been killed in a colliery in which Sir Ralph Milbanke had an interest, and he was called upon at the meeting to state the particulars of the accident. At that time there was such little expectation that any means could be devised to prevent the occurrence of these explosions, that the object of the gentlemen who convened the meeting, however humane in principle, was considered by the persons present as chimerical and visionary. The Society, however, amidst many difficulties and considerable discouragement, and a perpetual harass by the offer of impracticable schemes from every quarter, nevertheless persevered in their meetings, and succeeded in establishing a communication and correspondence with other Societies in different parts of the kingdom."[27]
"One of the projects offered was, that electrical machines should be employed, with ramifications to extend through all the departments of the collieries, and which were to be excited in discharging their fluid in constant succession, in order gradually to destroy the inflammable air. Many other suggestions were proposed, the principal of which were formed with the intention of purifying the air of the pits by chemical processes, or by forcing in large quantities of atmospheric air, through pipes and tunnels, &c.
"The Society, although it received some distinguished patronage, was not furnished with means sufficiently ample for exciting emulation by premiums, or even for defraying the expenses of intelligent artisans; and it unfortunately lost a considerable portion of its funds by the failure of the Wear Bank.
"Amongst the applications which more particularly excited the attention of the Society, was that of Mr. Ryan of Donegal, who objected to the principle upon which the working of collieries was carried on. He conceived that they should be originally constructed at the commencement of the working, with a view to admit the escape of the hydrogen gas to the highest parts of the colliery. He proposed to ventilate even the foulest pits, and the attention of the gentlemen proprietors, or occupiers of collieries, in the neighbourhood of Newcastle, was called upon at public meetings, and an enquiry set on foot with respect to the validity of his pretensions. Some gentlemen were even deputed to proceed into Staffordshire to ascertain the nature and extent of his services in that county, where he had been for some time employed. An offer was also made to place under his management the Hecton pit, at Hepburn, which was particularly foul; but a difference of opinion having arisen as to the efficacy of his plan, he did not consider himself sufficiently encouraged to proceed, and he left the country dissatisfied. He afterwards received the gold medal from the Society for promoting the Arts and Sciences."
The Society having as yet effected but little towards the great object of their deliberations, the chairman of the committee, Dr. Gray, who was generally acquainted with Sir Humphry Davy, judged it expedient to direct his attention to a subject, upon which, of all men of science, he appeared to be the best calculated to bring his extensive stores of chemical knowledge to a practical bearing.
As the life of this valuable man is now closed, and as every incident in it is interesting as connected with the advancement of philosophical knowledge, and especially of chemical discoveries important to the welfare of mankind, it may be worth while to enter into a review of the proceedings which were adopted upon this occasion, in order to trace the progress of the discoveries which were made, and the methods by which he arrived at his conclusions.
Dr. Gray, the chairman of the committee, having addressed to him a letter with a view to engage him in an investigation so important to society, received from him the following answer.
TO THE REVEREND DR. GRAY.
August 3, 1815.
SIR,
I had the honour of receiving the letter which you addressed to me in London, at this place, and I am much obliged to you for calling my attention to so important a subject.
It will give me great satisfaction if my chemical knowledge can be of any use in an enquiry so interesting to humanity, and I beg you will assure the Committee of my readiness to co-operate with them in any experiments or investigations on the subject.
If you think my visiting the mines can be of any use, I will cheerfully do so.
There appears to me to be several modes of destroying the fire-damp without danger; but the difficulty is to ascertain when it is present, without introducing lights which may inflame it. I have thought of two species of lights which have no power of inflaming the gas which is the cause of the fire-damp, but I have not here the means of ascertaining whether they will be sufficiently luminous to enable the workmen to carry on their business. They can be easily procured, and at a cheaper rate than candles.
I do not recollect any thing of Mr. Ryan's plan: it is possible that it has been mentioned to me in general conversation, and that I have forgotten it. If it has been communicated to me in any other way, it has made no impression on my memory.
I shall be here for ten days longer, and on my return South, will visit any place you will be kind enough to point out to me, where I may be able to acquire information on the subject of the coal gas.
Should the Bishop of Durham be at Auckland, I shall pay my respects to his Lordship on my return.
I have the honour to be, dear Sir, with much respect, your obedient humble servant,
H. Davy.
At Lord Somerville's, near Melrose, N. B.
TO THE SAME.
Melrose, August 18, 1815.
SIR,
I received your letter, which followed me to the Moors, where I have been shooting with Lord Somerville. I should have replied to it before this time, but we were in a part of the Highlands where there was no post. I am very grateful to you for the obliging invitation it contains.
I propose to leave the Tweed side on Tuesday or Wednesday, so that I shall be at Newcastle either on Wednesday or Thursday. If you will have the kindness to inform me by a letter, addressed at the Post Office, where I can find the gentleman you mention, I will call upon him, and do any thing in my power to assist the investigation in that neighbourhood.
I regret that I cannot say positively whether I shall be at Newcastle on Wednesday or Thursday; for I have some business at Kelso which may detain me for a night, or it may be finished immediately.
I am travelling as a bachelor, and will do myself the honour of paying my respects to you at Bishop-Wearmouth towards the end of the week.
I am, Sir, with much respect,
Your obedient humble servant,
H. Davy.
The gentleman alluded to in the preceding letter, and to whom Dr. Gray wished Sir H. Davy to apply, was Mr. Buddle, a person whose extensive practical knowledge has justly entitled him to be considered as the highest authority on all subjects connected with the art of mining, and who has conferred inestimable benefits on the mining interests by the introduction of successful methods of ventilation. The account of his interview with Sir H. Davy is communicated in the following letter.
MR. BUDDLE TO DR. GRAY.
Wall's-end Colliery, August 24, 1815.
SIR,
Permit me to offer my best acknowledgments for the opportunity which your attention to the cause of humanity has afforded me of being introduced to Sir Humphry Davy.
I was this morning favoured with a call from him, and he was accompanied by the Rev. Mr. Hodgson. He made particular enquiries into the nature of the danger arising from the discharge of the inflammable gas in our mines. I shall supply him with a quantity of the gas to analyze; and he has given me reason to expect that a substitute may be found for the steel mill, which will not fire the gas. He seems also to think it possible to generate a gas, at a moderate expense, which, by mixing with the atmospheric current, will so far neutralize the inflammable air, as to prevent it firing at the candles of the workmen.
If he should be so fortunate as to succeed in either the one or the other of these points, he will render the most essential benefit to the mining interest of this country, and to the cause of humanity in particular.
I have little doubt but it will be gratifying to you to be informed, that progress is making towards the establishment of a permanent fund for the relief of sufferers by accident and sickness in the collieries of this district.
I have the pleasure to remain, with great respect, Sir, your most obedient, humble servant,
John Buddle.
Sir H. Davy on his return to London, having been supplied by Mr. Buddle with various specimens of fire-damp, proceeded, in the first instance, to submit to a minute chemical examination the substance with which he had to contend.
In less than a fortnight, he informed Dr. Gray by letter, that he had discovered some new and unexpected properties in the gas, which had led to no less than four different plans for lighting the mines with safety.
TO THE REVEREND DR. GRAY.
Royal Institution, Oct. 30.
MY DEAR SIR,
As it was the consequence of your invitation that I endeavoured to investigate the nature of the fire-damp, I owe to you the first notice of the progress of my experiments.
My results have been successful far beyond my expectations. I shall enclose a little sketch of my views on the subject; and I hope in a few days to be able to send a paper with the apparatus for the committee.
I trust the Safe lamp will answer all the objects of the collier.
I consider this at present as a private communication. I wish you to examine the lamps I have had constructed, before you give any account of my labours to the committee.
I have never received so much pleasure from the result of any of my chemical labours; for I trust the cause of humanity will gain something by it.
I beg of you to present my best respects to Mrs. Gray, and to remember me to your son.
I am, my dear Sir, with many thanks for your hospitality and kindness when I was at Sunderland, your obliged servant,
H. Davy.
TO THE SAME.
London, October 31, 1815.
MY DEAR SIR,
I sent yesterday a sketch of my results on the fire-damp. We have lately heard so much of East[28] Shields, that by a strange accident I confounded it with Bishop-Wearmouth, and addressed your letter to East Shields.
I could not find any body to frank it, and you will find it a heavy packet; however, I could not lose a moment in giving you an account of results which I hope may be useful to humanity.
If my letter has not reached you, it will be found at the Post Office, East Shields.
With respects to Mrs. Gray, I am, my dear Sir, very sincerely yours,
H. Davy.
The sketch alluded to in the foregoing letter, has been kindly placed in my hands by the Bishop of Bristol; it possesses considerable interest as an original document, displaying his earliest views, and tending to illustrate the history of their progress.
"The fire-damp I find, by chemical analysis, to be (as it has been always supposed) a hydro-carbonate. It is a chemical combination of hydrogen gas and carbon, in the proportion of 4 by weight of hydrogen gas, and 11-1/2 of charcoal.
"I find it will not explode, if mixed with less than six times, or more than fourteen times its volume of atmospheric air. Air, when rendered impure by the combustion of a candle, but in which the candle will still burn, will not explode the gas from the mines; and when a lamp or candle is made to burn in a close vessel having apertures only above and below, an explosive mixture of gas admitted merely enlarges the light, and then gradually extinguishes it without explosion. Again,—the gas mixed in any proportion with common air, I have discovered, will not explode in a small tube, the diameter of which is less than 1/8th of an inch, or even a larger tube, if there is a mechanical force urging the gas through this tube.
"Explosive mixtures of this gas with air require much stronger heat for their explosion than mixtures of common inflammable gas.[29] Red-hot charcoal, made so as not to flame, if blown up by a mixture of the mine gas and common air, does not explode it, but gives light in it; and iron, to cause the explosion of mixtures of this gas with air, must be made white-hot.
"The discovery of these curious and unexpected properties of the gas, leads to several practical methods of lighting the mines without any danger of explosion.
"The first and simplest is what I shall call the Safe lamp, in which a candle or a lamp burns in a safe lantern which is air-tight in the sides, which has tubes below for admitting air, a chamber above, and a chimney for the foul air to pass through; and this is as portable as a common lantern, and not much more expensive. In this, the light never burns in its full quantity of air, and therefore is more feeble than that of the common candle.
"The second is the Blowing lamp. In this, the candle or lamp burns in a close lantern, having a tube below of small diameter for admitting air, which is thrown in by a small pair of bellows, and a tube above of the same diameter, furnished with a cup filled with oil. This burns brighter than the simple safe lamp, and is extinguished by explosive mixtures of the fire-damp. In this apparatus the candle may be made to burn as bright as in the air; and supposing an explosion to be made in it, it cannot reach to the external air.
"The third is the Piston lamp, in which the candle is made to burn in a small glass lantern furnished with a piston, so constructed as to admit of air being supplied and thrown into it without any communication between the burner and the external air: this apparatus is not larger than the steel-mill, but it is more expensive than the other, costing from twenty-two to twenty-four shillings.
"These lamps are all extinguished when the air becomes so polluted with fire-damp as to be explosive.
"There is a fourth lamp, by means of which any blowers may be examined in air in which respiration cannot be carried on: that is, the Charcoal lamp. This consists of a small iron cage on a stand, containing small pieces of very well burnt charcoal blown up to a red heat. This light will not inflame any mixtures of air with fire-damp.[30]
"Of these inventions, the Safe lamp, which is the simplest, is likewise the one which affords the most perfect security, and requires no more care or attention than the common candle, and when the air in mines becomes improper for respiration, it is extinguished, and the workmen ought immediately to leave the place till a proper quantity of atmospheric air can be supplied by ventilation.
"I have made many experiments on these lamps with the genuine fire-damp taken from a blower in the Hepburn Colliery, collected under the inspection of Mr. Dunn, and sent to me by the Reverend Mr. Hodgson. My results have been always unequivocal.
"I shall immediately send models of the different lamps to such of the mines as are exposed to danger from explosion; and it will be the highest gratification to me to have assisted by my efforts a cause so interesting to humanity."
Contrary to the wish expressed by Sir Humphry Davy, the foregoing communication was inadvertently read at a public meeting of the Coal-trade, which was held at Newcastle on the 3rd of November: a circumstance which occasioned some embarrassment at the time, but is satisfactorily explained in the following letter from Sir Humphry.
TO THE REVEREND DR. GRAY.
23, Grosvenor Street, Dec. 14, 1815.
MY DEAR SIR,
My communication to —— was, like that I made to you, intended to be private; he has however written to me to apologize for having made it known at Newcastle, stating, that having seen a notice of my results in the paper, the motive, as he conceived, for withholding it was at an end, as he considered my only reason for wishing to keep back my results from the public eye was the conviction that they might be rendered more perfect, and this I have now fully proved.
I trust I shall be able in a very few days to send you a model of a lantern nearly as simple as a common glass lantern, and which cannot communicate explosion to the fire-damp. I will send another to Newcastle, and I will likewise send you the copy of my paper, which you may reprint in any form you please; you will find my acknowledgments to you publicly stated.
My principles are these: First, a certain mixture of azote and carbonic acid prevents the explosion of the fire-damp, and this mixture is necessarily formed in the safe lantern;—Secondly, the fire-damp will not explode in tubes or feeders of a certain small diameter. The ingress into, and egress of air from my lantern is through such tubes or feeders; and therefore, when an explosion is artificially made in the safe lantern, it does not communicate to the external air.
I have made two or three lanterns of different forms. Experience must determine which will be the most convenient.
Should there be a little delay in sending them, it will be the fault of the manufacturer. It is impossible to conceive the difficulty of getting any thing made in London which is not in the common routine of business; and I should be very sorry to send you any thing imperfectly executed.
With best respects to Mrs. Gray, I am, my dear Sir,
Very sincerely your obliged servant,
H. Davy.
The paper alluded to in the preceding letter, entitled, "On the Fire-damp of Coal Mines, and on methods of lighting the mine so as to prevent its explosion," was read before the Royal Society on the 9th of November, 1815.
In this memoir he communicates the results of some chemical experiments upon the nature of the fire-damp, and announces the existence of certain properties in that gas, which had previously escaped observation, and which leads to very simple methods of lighting the mines without danger.
He confirms the opinion of Dr. Henry, and other chemists, as to the fire-damp being light carburetted hydrogen gas, and analogous to the inflammable gas of marshes; but he found that the degree of its combustibility differed most materially from that of the other common inflammable gases, which it is well known will explode by the contact of both red-hot iron and charcoal; whereas well-burned charcoal, ignited to the strongest red heat, did not explode any mixture of the air and of the fire-damp; and a fire made of well-burned charcoal, that is to say, of charcoal that will burn without flame, was actually blown up to whiteness by an explosive mixture containing the fire-damp without producing its inflammation.[31] An iron rod also, at the highest degree of red heat, and even at the common degree of white heat, did not inflame explosive mixtures of the fire-damp; but when in brilliant combustion, it produced the effect.
He moreover found that the heat produced by the combustion of the fire-damp was much less than that occasioned by most other inflammable gases under similar circumstances; and hence its explosion was accompanied with comparatively less expansion: a circumstance of obvious importance in connection with the propagation of its flame.
Numerous experiments were likewise instituted by him with a view to determine the proportions of air with which the fire-damp required to be mixed, in order to produce an explosive atmosphere; and he found the quantity necessary for that purpose to be very considerable; even when mixed with three or nearly four times its bulk of air, it burnt quietly in the atmosphere, and extinguished a taper. When mixed with between five and six times its volume of air, it exploded freely. The mixture which seemed to possess the greatest explosive power was that of seven or eight parts of air to one of gas.
On adding azote and carbonic acid in different proportions to explosive mixtures of fire-damp, it was observed that, even in very small quantities, these gases diminished the velocity of the inflammation, or altogether destroyed it. In this stage of the enquiry, the important fact was discovered, that explosive mixtures could not be fired in metallic tubes of certain lengths and diameters.[32] In exploding, for instance, a mixture of one part of gas from the distillation of coal, and eight parts of air, in a tube of a quarter of an inch in diameter and A foot long, more than a second was required before the flame reached from one end of the tube to the other; and not any mixture could be made to explode in a glass tube of one-seventh of an inch in diameter. In pursuing these experiments, he found that, by diminishing its diameter, he might in the same ratio shorten the tube without danger; and that the same principle of security was obtained by diminishing the length and increasing the number of the tubes, so that a great number of small apertures would not pass explosion when their depth was equal to their diameter. This fact led him to trials upon sieves made of wire-gauze, or metallic plates perforated with numerous small holes, and he found that it was impossible to pass explosions through them.[33]
In reasoning upon these several phenomena, it occurred to him, that as a high temperature was required for the inflammation of the fire-damp, and as it produced in burning, comparatively, a small degree of heat, the effect of carbonic acid and azote, as well as that of the surfaces of small tubes, in preventing its explosion, depended upon their cooling powers; that is to say, upon their lowering the temperature of the exploding mixture to such a degree, that it was no longer sufficient for its continuous inflammation. In support of this theory, he ascertained that metallic tubes resisted the passage of the flame more powerfully than glass tubes of similar lengths and diameters, metal being the better conductor of heat; and that carbonic acid was more effective than azote in depriving the fire-damp of its explosive power, in consequence, as he considered, of its greater capacity for heat, and likewise of a higher conducting power connected with its greater density.
In this short statement, the reader is presented with the whole theory and operation of the Safety-lamp, which is nothing more than an apparatus by which the inflammable air, upon exploding in its interior, cannot pass out without being so far cooled, as to deprive it of the power of communicating inflammation to the surrounding atmosphere. The principle having been once discovered, it was easy to adopt and multiply practical applications of it.
From the result of these researches, it became at once evident, that to light mines infested with fire-damp, with perfect security, it was only necessary to use an air-tight lantern, supplied with air from tubes of small diameter, through which explosions cannot pass, and with a chimney, on a similar principle, at the upper part, to carry off the foul air. A common lantern, to be adapted to the purpose, merely required to be made air-tight in the door and sides, and to be furnished with the chimney, and the system of safety apertures below and above the flame of the lamp. Such, in fact, was Davy's first Safety-lamp; and having afterwards varied the arrangement of the tubes in different ways, he at length exchanged them for canals, which consisted of close concentric hollow metallic cylinders of different diameter, so placed together as to form circular canals of the diameter of from one-twenty-fifth to one fortieth of an inch; and of an inch and seven-tenths in length; by which air is admitted in much larger quantities than by the small tubes, and they are moreover much superior to the latter in practical application. He also found, that longitudinal air-canals of metal might be employed with the same security as circular canals; and that a few pieces of tin plate, soldered together with wires to regulate the diameter of the canal, answered the purpose of the feeder or safe chimney, as well as drawn cylinders of brass.
The subjoined explanatory sketches will assist in rendering the scheme intelligible, and obviate the possibility of any misconception of the subject.
Fig. 1. represents the first Safe lantern, with its air-feeder and chimney furnished with safety metallic canals. The sides are of horn or glass, made air-tight by putty or cement. A. is the lamp through which the circular air-feeding canals pass. B. is the chimney containing four such canals; above it is a hollow cylinder, with a cap to prevent dust from passing into the chimney. C. is the hole for admitting oil. F. is the rim round the bottom of the lantern, to enable it to bear motion.
Fig. 2. exhibits an enlarged view of the safety concentric canals, which, if one-twenty-fifth of an inch in diameter, must not be less than two inches in exterior circumference, and one-seventh of an inch high.
Fig. 3. exhibits the longitudinal safety canals.
Fig. 4. represents a Safety-lamp having a glass chimney, covered with tin-plate, and the safety apertures in a cylinder with a covering above: the lower part is the same as in the lantern.
Fig. 5. A glass tube furnished with flame sieves, in which a common candle may be burnt. A A. the flame sieves. B. a little plate of metal to prevent the upper flame sieve from being acted on by the current of hot air.
During the short visit of Sir Humphry Davy at Bishop Wearmouth, he saw the lamp which Dr. Clanny was then engaged in perfecting. It has been already observed, that it was secured against the effects of fire-damp by being supplied with atmospheric air previously conveyed through water.[34] The machinery of this lamp was far too cumbrous to be of general use; but its inventor was justly commended by Davy for his ingenuity and perseverance. It unfortunately happened that, in consequence of some erroneous representations made to Dr. Clanny, he received the impression that Sir Humphry had not been disposed to treat his invention with sufficient respect, nor had given him the credit to which he was so justly entitled. This suspicion, which had been long industriously kept alive, was however ultimately removed.
The following letter refers to this unfortunate circumstance. I have adverted to it in these memoirs, for the purpose of showing what an unfair spirit of rivalry, and what a succession of petty jealousies were excited by those generous and disinterested labours of Davy, which ought to have called forth nothing but the most lively expressions of gratitude for his services, and admiration of his genius.
TO THE REVEREND DR. GRAY.
23, Grosvenor Street, December 13.
MY DEAR SIR,
A Friend of mine has sent me a newspaper—the Tyne Mercury, containing a very foolish libel upon me. It states, amongst other things, that I did not mention Dr. Clanny, or his lamp, in my late paper read before the Royal Society; whereas I mentioned his lamp as a very ingenious contrivance, and named him amongst the gentlemen who obligingly furnished me with information upon the subject.
It will be needless for me to point out to you that my lamp has no one principle in common with that of Dr. Clanny. He forces in his air through water by bellows. In mine, the air passes through safety canals without any mechanical assistance. Mine is a common lantern made close, and furnished with safety canals.
I hope I shall not hear that Dr. Clanny has in any way authorized or promoted so improper a statement as that in the Tyne Mercury; indeed, I do not think it possible.
I have at last obtained a complete model of my lamp, after many disappointments from the instrument-maker. I hope in a few days to send you a Safe lantern, as portable as a common-made one, and the perfect security of which is demonstrable.
I am, my dear Sir, your sincerely obliged,
H. Davy.
TO THE SAME.
Grosvenor Street, December 15.
MY DEAR SIR,
I shall inclose the first sheet of my paper, and shall be glad to preface it by some observations when you reprint it.
I shall forward my lanterns and lamps to you in a few days. They are absolutely safe; and if the miners have any more explosions from their light, it will be their own fault.
You will find, when you see my construction, that the principles as well as the execution are entirely new.
You will find in the second sheet of my paper, which I hope to be able to send to-morrow, the principles of security, and its limits unfolded.
I am, my dear Sir, very sincerely yours,
H. Davy.
TO THE SAME.
London, January 1, 1816.
MY DEAR SIR,
I fear you will have accused me of procrastination in delaying to send you my papers and my lamps.
The papers read to the Royal Society have been printed; but during the period that has elapsed since I last wrote to you, I have made a discovery much more important than those which I have already had the honour of communicating to you.
I have made very simple and economical lanterns, and candle guards, which are not only absolutely safe, but which give light by means of the fire-damp, and which, while they disarm this destructive agent, make it useful to the miner.
This discovery is a consequence of that which I communicated to you in my last letter on the wire sieves. I hope to be able to send you on Wednesday the printed account of my results, together with models of lamps which will burn and consume all explosive mixtures of the fire-damp.
I have at last finished my enquiries with perfect satisfaction to myself, and I feel highly obliged to you for having called my attention to a subject where my labours will, I hope, be of some use.
I am, my dear Sir, very sincerely yours,
H. Davy.
It is impossible to approach the consideration of this last, the most signal and splendid of his triumphs, without feelings of the highest satisfaction. He had already, as we have seen, disarmed the fire-damp of its terrors, it only remained for him to enlist it into his service. The simple means by which this was effected are as interesting as their results are important.[35]
Davy had previously arrived at the fact, that wire-gauze might be substituted as air-feeders to the lamp, in the place of his tubes or safety canals; but not until after the lapse of several weeks, did the happy idea of constructing the lamp entirely of wire-gauze occur to him:—the history of this elaborate enquiry affords a striking proof of the inability of the human mind to apprehend simplicities, without a process of complication which works as the grappling machinery of truth.
His original lamp with tubes or canals, as already described, was perfectly safe in the most explosive atmosphere, but its light was necessarily extinguished by it; whereas in the wire-gauze cage, the fire-damp itself continues to burn, and thus to afford to the miner a useful light, while he is equally secured from the fatal effects of explosion.
All then required for his guidance and protection in the darkness of the mine, are candles or lamps surrounded by small wire cages, which will at once supply air to the flame, and light to the miner; they may be obtained for a few pence, and be variously modified as circumstances may render necessary.
The reader is here presented with a sketch of the gauze instrument, in its first and simplest form. The original lamp is preserved in the laboratory of the Royal Institution.
Nothing now remained but to ascertain the degree of fineness which the wire-gauze ought to possess, in order to form a secure barrier against the passage of flame. For this purpose, Davy placed his lighted lamps in a glass receiver, through which there was a current of atmospherical air, and by means of a gasometer filled with coal gas, he made the current of air which passed into the lamp more or less explosive, and caused it to change rapidly or slowly at pleasure, so as to produce all possible varieties of inflammable and explosive mixtures; and he found that iron wire-gauze composed of wires from one-fortieth to one-sixtieth of an inch in diameter, and containing twenty-eight wires, or seven hundred and eighty-four apertures to the inch, was safe under all circumstances in atmospheres of this kind; and he consequently employed that material in guarding lamps for the coal mines, where, in January 1816, they were immediately adopted, and have long been in general use.
Observations upon them in their working state, and upon the circumstances to which they are exposed, have led to a few improvements or alterations, merely connected with the modes of increasing light or diminishing heat, which were obvious from the original construction.
The annexed woodcut represents the lamp which is in present use. A is a cylinder of wire-gauze, with a double top, securely and carefully fastened, by doubling over, to the brass rim B, which screws on to the lamp C. The whole is protected by strong iron supports D, to which a ring is affixed for the convenience of carrying it.
In a paper read before the Royal Society, on the 23rd of January 1817, entitled, "Some new Experiments and Observations on the Combustion of Gaseous Mixtures, with an Account of a method of preserving a continued Light in mixtures of inflammable Gases and Air without Flame," Sir H. Davy announces the application of a principle which he had discovered in the progress of his researches for increasing the utility of the Safety-lamp, and which, a century ago, would have unquestionably exposed its author to the charge of witchcraft.
Having ascertained that the temperature of flame is infinitely higher than that necessary for the ignition of solid bodies, it appeared to him probable that, in certain combinations of gaseous bodies, although the increase of temperature might not be sufficient to render the gaseous matters themselves luminous, they might nevertheless be adequate to ignite solid matters exposed to them. During his experiments on this subject, he was led to the discovery of the curious phenomenon of slow combustion without flame. He observes, that there cannot be a better mode of illustrating the fact, than by an experiment on the vapour of ether or of alcohol. Let a few coils of wire of platinum of the one-sixtieth or one-seventieth of an inch be heated by a hot poker or candle, and let it be brought into the glass; it will presently become glowing, almost white hot, and will continue so, as long as a sufficient quantity of vapour and of air remain in the glass.[36]
This experiment on the slow combustion of ether is accompanied with the formation of a peculiar acrid and volatile substance possessed of acid properties, which has been particularly examined by Mr. Daniell, who, having at first regarded it as a new acid, proposed for it the name of Lampic acid, in allusion to the researches which led to its discovery; he has, however, since ascertained that its acidity is owing to the acetic acid, which is combined with some compound of carbon and hydrogen, different both from ether and alcohol.
The phenomena of slow combustion, as exhibited in certain states of the mine, by the Safety-lamp, are highly curious and interesting.
By suspending some coils of fine wire of platinum[37] above the wick of his lamp, the miner will be supplied with light in mixtures of fire-damp no longer explosive; for should his flame be extinguished by the quantity of fire-damp, the little coil of platinum will begin to glow with a light sufficiently bright to guide him in what would otherwise be impenetrable darkness, and to lead him into a purer atmosphere, when the heat thus increased will very frequently be sufficient to rekindle his lamp!
In this case it will be readily perceived, that the combustion of the fire-damp is continued so slowly, and at so low a temperature, as not to be adequate to that ignition of gaseous matter which constitutes flame, although it excites a temperature sufficient to render platinum wire luminous.
Sir Humphry Davy observes, that there never can be any danger with respect to respiration, whenever the wire continues ignited; for even this phenomenon ceases when the foul air forms about two-fifths of the volume of the atmosphere.
The experiment, as originally performed by the illustrious chemist, is so interesting and instructive, that I shall here relate it in his own words.
"I introduced into a wire-gauze Safe lamp a small cage made of fine wire of platinum of one-seventieth of an inch in thickness, and fixed it by means of a thick wire of the same metal about two inches above the wick which was lighted. I placed the whole apparatus in a large receiver, in which, by means of a gas-holder, the air could be contaminated to any extent with coal gas. As soon as there was a slight admixture of coal gas, the platinum became ignited; the ignition continued to increase till the flame of the wick was extinguished, and till the whole cylinder became filled with flame; it then diminished. When the quantity of coal gas was increased, so as to extinguish the flame, at the moment of the extinction the cage of platinum became white hot, and presented a most brilliant light. By increasing the quantity of the coal gas still farther, the ignition of the platinum became less vivid: when its light was barely sensible, small quantities of air were admitted, its heat speedily increased; and by regulating the admission of coal gas and air, it again became white hot, and soon after lighted the flame in the cylinder, which as usual, by the addition of more atmospherical air, rekindled the flame of the wick."
I have thus related, somewhat in detail, the history of a discovery, which, whether considered in relation to its scientific importance, or to its great practical value, must be regarded as one of the most splendid triumphs of human genius. It was the fruit of elaborate experiment and close induction; chance, or accident, which comes in for so large a share of the credit of human invention, has no claims to prefer upon this occasion; step by step, may he be followed throughout the whole progress of his research, and so obviously does the discovery of each new fact spring from those that preceded it, that we never for a moment lose sight of our philosopher, but keep pace with him during the whole of his curious enquiry.
He commenced, as we have seen, with ascertaining the degree of combustibility of the fire-damp, and the limits in which the proportions of atmospheric air and carburetted hydrogen can be combined, so as to afford an explosive mixture. He was then led to examine the effects of the admixture of azote and carbonic acid gas; and the result of those experiments furnished him with the basis of his first plan of security. His next step was to enquire whether explosions of gas would pass through tubes; and on finding that this did not happen, if the tubes were of certain lengths and diameters, he proceeded to examine the limits of such conditions, and by shortening the tubes, diminishing their diameters, and multiplying their number, he at length arrived at the conclusion, that a simple tissue of wire-gauze afforded all the means of perfect security; and he constructed a lamp, which has been truly declared to be as marvellous in its operation, as the storied lamp of Aladdin, realizing its fabled powers of conducting in safety, through "fiends of combustion," to the hidden treasures of the earth. We behold a power which, in its effects, seemed to emulate the violence of the volcano and the earthquake, at once restrained by an almost invisible and impalpable barrier of network—we behold, as it were, the dæmon of fire taken captive by Science, and ministering to the convenience of the miner, while harmlessly fluttering in an iron cage.
And yet, wonderful as the phenomenon may appear, his experiments and reasonings have demonstrated, that the interruption of flame by solid tissues permeable to light and air, depends upon no recondite or mysterious cause, but simply upon their cooling powers, which must always be proportional to the smallness of the mesh, and the mass of the metal.
When it is remembered that the security thus conferred upon the labouring community, is not merely the privilege of the age in which the discovery was effected, but must be extended to future times, and continue to preserve human life as long as coal is dug from our mines, can there be found in the whole compass of art or science, an invention more useful and glorious?
The wire-gauze lamp has now been several years extensively used in the mines, and the most satisfactory and unequivocal testimonies have been published of the complete security which it affords. They have amongst the miners obtained the name of Davys; and such is the confidence of the work men in their efficacy, that by their aid they enter the most explosive atmospheres, and explore the most remote caverns, without the least dread of their old enemy the fire-damp.
Into the mines of foreign countries the Safety-lamp has been introduced with similar success; and the illustrious discoverer has been repeatedly gratified by accounts of the enthusiasm with which his invention has been adopted in various parts of Europe.[38]
Nor is the utility of this invention limited to the operations of mining. In gas manufactories, spirit warehouses,[39] or druggists' laboratories, and in various other situations, where the existence of an explosive atmosphere[40] may expose persons to danger, the Safety-lamp may be advantageously used; and as science proceeds in multiplying the resources of art, this instrument will no doubt be found capable of many new applications.
By the permission of the President and Council of the Royal Society, several accounts of these researches, and of the invention and use of the Safety-lamp were printed, and circulated through the coal districts.
It might have been fairly expected that, in a district which had been so continually and so awfully visited by explosions, against which no human foresight had as yet been able to provide a remedy, the disinterested services of the greatest chemist of the age would at least have been received without a dissentient voice, and that his invention of security would have escaped the common fate of all great discoveries, and been accepted with every homage of respect and gratitude; but the inventor of the Safety-lamp was doomed to encounter a bitter hostility from persons whom a spirit of rivalry, or a feeling of hopeless emulation, had cemented into a faction.
From the period of the first announcement of the Safety-lamp, a prejudice against its use was industriously circulated amongst the miners; and some persons even maintained the monstrous proposition, that any protection against the explosions of fire-damp would injure more than it could serve the collier, by inducing him to resume abandoned works, and thus continually to inhale a noxious atmosphere.
The utility of the lamp having been established, in spite of every opposition, the claims of Sir H. Davy to its invention were next publicly challenged.
It will hereafter be scarcely believed that an invention so eminently philosophic, and which could never have been derived but from the sterling treasury of science, should have been claimed in behalf of an engine-wright of Killingworth, of the name of Stephenson—a person not even professing a knowledge of the elements of chemistry. As the controversy to which this claim gave birth has long since subsided, I would willingly have treated it as a passing cloud, had not its shadow remained. The circumstances, however, of the transaction stand recorded in the Magazines of the day, and the biographer of Davy would compromise his rights, by omitting to notice the attempts that have been made to invalidate them.
The claims which were made for the priority of Mr. Stephenson's invention of the Safety-lamp were urged in several communications in the Newcastle Courant. It has been said in reply, that if dates were taken as evidence, not merely of priority, but of originality of invention, it must follow that Mr. Stephenson's lamp was derived from that of Sir H. Davy. With regard to the first of Stephenson's lamps, the only one upon which the shadow even of a claim can be founded, it is unnecessary for the friends of truth to adopt such a line of defence; indeed, after a deliberate examination of all that has been published on the subject, I am very willing to believe that Mr. Stephenson did construct the lamp which dates its origin from the 21st of October 1815, without any previous knowledge of the conclusions at which Davy had arrived; for it was first announced to the Coal-trade by Mr. R. Lambert on the 3rd of November, to the very meeting at which Sir H. Davy's private letter was inadvertently read.—But what were the principles, and what the construction of this lamp?
It would appear that Mr. Stephenson had entertained some vague notion of the practicability of consuming the fire-damp as fast as it entered the lamp, and that if admitted only in small quantities, it would not explode the surrounding atmosphere: for effecting this object, he constructed a lamp with an orifice, over which was placed a slide, by the movement of which the opening could be enlarged, or diminished, and the volume of fire-damp to be admitted into the lamp regulated according to circumstances. Now such a lamp could be nothing else than an exploding lamp; for to make it burn in common air, the orifice must have been so wide that, on going into an explosive atmosphere, the combustion in the interior could not have failed to pass it, and to have exploded the mine. Here then is a safety-lamp, which as long as it is safe, will not burn, and the moment it begins to burn, it becomes unsafe!
The testimonies in favour of the security afforded by this lamp were evidently procured from persons who were not only ignorant of the principles of its construction, but of the methods to be pursued for ascertaining its safety. I am surely justified in such a statement, when, instead of an explosive mixture, I find them throwing in pure fire-damp, which will always extinguish flame, whether burning in a safe or unsafe lamp.
The importance and utility of Davy's lamp having been completely established by the severest ordeals, the general gratitude of the country began more publicly to display itself, and a very strong feeling prevailed, that some tribute of respect should be paid to its inventor; in accordance with which, a deputation of the Coal-owners of the rivers Tyne and Wear, and of the ports of Hartley and Blyth, requested the honour of an interview with Sir H. Davy; upon which occasion they presented him with the following letter, containing an expression of the thanks of the Coal-owners.
TO SIR HUMPHRY DAVY, LL.D. &c.
Newcastle, March 25, 1816.
SIR,
As chairman of the general meeting of proprietors of coal-mines upon the rivers Tyne and Wear, held in the Assembly-rooms at Newcastle, on the 18th instant, I was requested to express to you their united thanks and approbation for the great and important discovery of your Safety-lamp for exploring mines charged with inflammable gas, which they consider admirably calculated to obviate those dreadful calamities, and the lamentable sacrifice of human life, which of late years have so frequently occurred in the mines of this country.
They are most powerfully impressed with admiration and gratitude towards the splendid talents and brilliant acquirements that have achieved so momentous and important a discovery, unparalleled in the history of mining, and not surpassed by any discovery of the present age; and they hope that, whilst the tribute of applause and glory is showered down upon those who invent the weapons of destruction, this great and unrivalled discovery for preserving the lives of our fellow-creatures, will be rewarded by some mark of national distinction and honour. I am, Sir,
Your most obedient humble Servant,
George Waldie, Chairman.
A plan, however, was under consideration for recording the admiration and gratitude of the Coal-owners, by a more permanent and solid memorial. The nature of this proposition will be best disclosed by inserting the following letter from Mr. Buddle.
TO THE REV. DR. GRAY.
Wall's-End Colliery, August 27, 1816.
SIR,
As I know that you feel much interest in all matters relating to Sir H. Davy's Safety-lamp, I trust you will excuse the liberty I take in informing you, that the Committee of the Tyne, approving highly of the suggestion, that some mark of acknowledgment and respect should be presented to Sir Humphry by the Coal-trade of this country, for the happy invention of his lamp, have convened a general meeting of Coal-owners, to be holden at my office in Newcastle, on Saturday next the 31st instant, at twelve o'clock, to take the subject into consideration.
I should have sooner informed you of this proposed meeting, had I not been detained in Cumberland until yesterday; but I shall have the pleasure of transmitting to you a copy of its resolutions.
I am sure that you will be gratified to learn that the lamps continue to go on as well as possible. We now have twelve dozen of them in daily use at this place. I have the pleasure to remain, with the greatest respect, Sir,
Your most obedient humble Servant,
John Buddle.
TO THE SAME.
Newcastle, September 7, 1816.
SIR,
I now have the pleasure of sending you a copy of the Resolutions of the general meeting of Coal-owners on the 31st instant, and shall take the liberty of informing you of the future progress of this affair.
Sir Humphry did me the honour yesterday to accompany me through the workings of a coal-pit at Wall's-End, when I had an opportunity of witnessing several interesting experiments on his Safety-lamp; and I have the satisfaction to add, that I believe he has now advanced it to the highest degree of perfection.
I am, respectfully, Sir,
Your humble Servant,
John Buddle.
The satisfactory result of this visit Sir Humphry communicated to Mr. Lambton, now Lord Durham; and I shall take this opportunity to state, that for this as well as for several other letters I shall hereafter have occasion to introduce, I am indebted to that noble Lord, through the kind application of my friend Sir Cuthbert Sharp.
TO J. G. LAMBTON, ESQ. M.P.
Newcastle, September 9, 1816.
MY DEAR SIR,
Since I last had the pleasure of seeing you, I have examined the workings in the Wall's-End collieries by the lamps, and have tried them in various explosive mixtures.
On Sunday, I went with Mr. Buddle to your blower, with the single lamps furnished with small tin reflectors. This simple modification rendered them perfectly safe, even in the furious blow-pipe, and at the same time increased their light. Nothing could be more satisfactory than all the trials.
I have left a paper in the hands of the Rev. J. Hodgson, which will be printed in a day or two; and I have desired him to send you ten copies, or as many more as you may like to have.
I trust I have now left nothing undone as to the perfect security of the lamps, under every possible circumstance.
I feel highly gratified that it was at your mines I effected the only object that remained to be accomplished—that of guarding against blowers meeting fresh currents of air.
I thank you very sincerely for the interest you have taken in the lamps, connected with my efforts to render them applicable in all cases. I remain, &c.
H. Davy.
On the 19th of October 1816, a letter appeared in the Durham County Advertiser, dated "Gosforth, August 22nd, 1816," in the name of Mr. W. Brandling, in which, alluding to the Resolutions of the Coal-owners of the 31st of August, he expresses a wish that a strict examination should take place previous to the adoption of a measure which might convey a decided opinion to the public, as to the person to whom the invaluable discovery of the Safety-lamp is actually due. "The conviction," says he, "upon my mind is, that Mr. George Stephenson, of Killingworth Colliery, is the person who first discovered and applied the principle upon which safe lamps may be constructed; for, whether the hydrogen gas is admitted through capillary tubes, or through the apertures of wire-gauze, which may be considered as merely the orifices of capillary tubes, does not, as I conceive, in the least affect the principle.
"In the communications I have seen from Sir H. Davy, no dates are mentioned; and it is by a reference to them only that the question can be fairly decided. For the information of the Meeting, therefore, I shall take the liberty of enclosing some which I received from Mr. Stephenson, to the correctness of which, as far as I am concerned, I can bear testimony; at the same time I beg leave to add, that the principle of admitting hydrogen gas in such small detached portions that it would be consumed by combustion,[41] was, I understand, stated by him to several gentlemen, as the idea he had embraced two months before his lamp was originally constructed."
Mr. Brandling then proceeds to state, that the Killingworth lamp, with a tube to admit the air, and a slide at the bottom of such tube to regulate the quantity to be admitted, was first tried in the Killingworth pits on Saturday October the 21st, 1815; but not being found to burn well, another was ordered the same day with three capillary tubes to admit the air; and on being tried in the mine on the 4th of November following, was found to burn better and to be perfectly safe.[42] On the 17th of November, it was tried[43] at Killingworth office with inflammable air before Richard Lambert, Esq.; and on the 24th of the same month, before C. J. Brandling, Esq. and Mr. Murray.
"On the 30th of November," he says, "a lamp was tried in the mine, in which the air was admitted by means of a double row of small perforations, and found to be perfectly safe, and to burn extremely well."[44]
At an adjourned Meeting of the Coal-owners, held on the 11th of October 1816, J. G. Lambton, Esq. M.P. in the chair; Mr. William Brandling moved—"That the meeting do adjourn, until, by a comparison of dates, it shall be ascertained whether the merit of the Safety-lamp belongs to Sir Humphry Davy or to Mr. George Stephenson."
On the question being put thereon, THE SAME PASSED IN THE NEGATIVE.
A great number of the Coal-owners, instead of pursuing the idea which had at first been suggested, of a general contribution on the vend, immediately commenced a subscription of individual proprietors of coal-mines; a measure which, it was thought, would express more distinctly and unequivocally the opinion of the trade as to the merit of the invention. The plan is developed in the following letter.
TO THE REVEREND DR. GRAY.
Wall's-End Colliery, October 27, 1816.
SIR,
It is the anxious wish of almost every individual in the trade to compliment Sir Humphry Davy, in that way which may be most grateful to his feelings.
It has been suggested that the object will be best attained by substituting an individual (colliery) subscription, instead of the proposed contribution on the vend; and it will at the same time show more distinctly the real opinion of the trade as to the merit of the invention.
This idea was not suggested till yesterday afternoon, and of course there has been but little time to communicate it to the several Coal-owners; but all who have heard of the plan approve of it.
To facilitate the business, the committee have formed the annexed scale of contribution.[45]
I trust, Sir, you will excuse the trouble which I have given you on this subject; but I am aware that you must feel interested in it; and I hope, Sir, you will allow me to add, that I am fully sensible of the obligation which the Coal trade is under to yourself, for having drawn Sir H. Davy's attention to that particular line of investigation, which has led to the important discovery of the Safety-lamp. I am, Sir, with the greatest respect, your most obedient humble servant,
John Buddle.
Some slight alterations were afterwards made in this scheme, in consequence of a wish having been expressed that the Bishop of Durham and the Duke of Northumberland should take the lead in a subscription. The following letter conveys some farther information upon this subject.
TO THE REVEREND DR. GRAY.
Newcastle, January 11, 1817.
SIR,
I have to acknowledge the receipt of your letter of the 9th instant, communicating the intention of the Reverend the Dean and Chapter of Durham, to subscribe fifty guineas towards the plate to be presented to Sir H. Davy, which, together with two hundred guineas from the Coal-owners of the Wear, makes the subscription amount to nearly £1500, and I shall expect some farther subscriptions.
I am sure it will afford you satisfaction to learn that the lamps still continue to give the most gratifying proofs of the advantages resulting from their invention, and that not a single inch of human skin has been lost by fire, wherever they have been used.
Sir Humphry has just made another important improvement in the lamp, by constructing the cylinder of twisted wire-gauze. Lamps thus constructed, possess the singular property of not becoming red-hot, under any circumstances of exposure to explosive mixtures, whether urged by a blast, or in a state of rest. I am with great respect, Sir, your most obedient humble servant,
John Buddle.
It may be collected from the following letter, that the Committee, in announcing to Sir H. Davy the intended present of plate, delicately sounded him as to the form in which it would be most agreeable to him.
TO N. CLAYTON, ESQ.
Grosvenor Street, March 23, 1817.
SIR,
On my return to town, after an absence of some days, I found the letter of March the 13th, with which you honoured me, at the Royal Institution. I shall not lose a moment in replying to it, and in expressing my grateful feelings for the very flattering communication it contains.
The gentlemen interested in the coal-mines of the two rivers Tyne and Wear, cannot offer me any testimony of their kindness, which I shall not receive with infinite pleasure.
I hardly know how to explain myself on the particular subject of your letter; but as the Committee express themselves satisfied as to the utility of the Safety-lamp, I can only desire that their present, as it is highly honourable to me, should be likewise useful to my friends, and a small social circle, which it would be as a dinner-service for ten or twelve persons.
I wish that even the plate from which I eat should awaken my remembrance of their liberality, and put me in mind of an event which marks one of the happiest periods of my life.
I cannot find any language sufficiently strong to express my thanks to the gentlemen for the manner in which they have distinguished my exertions in their cause, and in the cause of humanity. I have the honour to remain, &c.
H. Davy.
To revert once again to the faction—for such I must denominate it—which, in opposition to the most unequivocal evidence, continued to support the unjust claims of Mr. Stephenson; it would appear from various letters in my possession, that the feelings of Davy were greatly exasperated by this ungenerous conduct.
I shall introduce one of these letters, playful in the midst of its wrath, addressed to Mr. Lambton, the friend[46] of his youth, and the manly and kind supporter of his scientific character, in the hour of persecution.
TO J. G. LAMBTON, ESQ. M.P.
Queen Square, Bath, Oct. 29, 1816.
MY DEAR SIR,
The severe indisposition of my wife has altered my plans. Your letter slowly followed me here.
Mr. —— is one of the persons who, after I had advanced a principle of security for a lamp, came upon the ground to endeavour to jockey me. I was not looking to a prize, I merely came forward to show an animal, the breed of which might be useful, when Mr. ——, Dr. ——, &c. brought their sorry jades, which had never before been seen or heard of, to kick at my blood mare.
I never heard a word of George Stephenson and his lamps till six weeks after my principle of security had been published; and the general impression of the scientific men in London, which is confirmed by what I heard at Newcastle, is, that Stephenson had some loose idea floating in his mind, which he had unsuccessfully attempted to put in practice till after my labours were made known;—then, he made something like a safe lamp, except that it is not safe, for the apertures below are four times, and those above, twenty times too large; but, even if Stephenson's plans had not been posterior to my principles, still there is no analogy between his glass exploding machine, and my metallic tissue, permeable to light and air, and impermeable to flame.
I am very glad that you attended the meeting; your conduct at no very distant period will be contrasted with that of some great coal-proprietors, who find reasons for their indifference, as to a benefit conferred upon them, in insinuations respecting the claims of Dr. Clanny, Mr. Stephenson, and others.
Where men resolve to be ungrateful, it is natural that they should be illiberal; and illiberality often hardens into malignity.
I shall receive any present of plate under your auspices, and those of the Committee over which you preside, with peculiar satisfaction. It will prove to me that my labours have not been disregarded by men of whose good opinion I am proud.
I hope you will not blame me for not taking any notice of the attacks of my enemies in the North. I have no desire to go out of my way to crush gnats that buzz at a distance, and do not bite me, or to quarrel with persons who shoot arrows at the moon, and believe, because they have for an instant intercepted a portion of her light, that they have hit their mark. I am sensible to the circumstances under which you attended the meeting.
I offer you my sincere congratulations, and ardent wishes that you may enjoy all possible happiness.
Believe me, &c.
H. Davy.
On the 13th of September 1817, Sir Humphry Davy being expected to pass through Newcastle on his return from Scotland, preparations were made, and notice given of a dinner which it was proposed should take place on the 25th instant, for the purpose of presenting to the illustrious philosopher the service of plate which had been prepared for his acceptance.
Upon this gratifying occasion, a very large party assembled at the Queen's Head, consisting of a numerous and respectable body of Coal-owners, and such other gentlemen as had interested themselves during the progress of the investigation, or taken an active part in promoting the introduction of the lamp into the mines.
After the dinner had concluded, and certain toasts of form had been drunk, Mr. Lambton, who filled the chair on the occasion, rose, and on presenting the service of plate to the illustrious guest, addressed him, in a tone of great animation and feeling, in nearly the following terms:
"Sir Humphry,—It now becomes my duty to fulfill the object of the meeting, in presenting to you this service of plate, from the Coal-owners of the Tyne and Wear, as a testimony of their gratitude for the services you have rendered to them and to humanity.
"Your brilliant genius, which has been so long employed in an unparalleled manner, in extending the boundaries of chemical knowledge, never accomplished a higher object, nor obtained a nobler triumph.
"You had to contend with an element of destruction which seemed uncontrollable by human power; which not only rendered the property of the coal-owner insecure, but kept him in perpetual alarm for the safety of the intrepid miner in his service, and often exhibited to him the most appalling scenes of death, and heart-sickening misery.
"You have increased the value of an important branch of productive industry; and, what is of infinitely greater importance, you have contributed to the lives and persons of multitudes of your fellow-creatures.
"It is now nearly two years that your Safety-lamp has been used by hundreds of miners in the most dangerous recesses of the earth, and under the most trying circumstances. Not a single failure has occurred—its absolute security is demonstrated. I have, indeed, deeply to lament more than one catastrophe, produced by fool-hardiness and ignorance, in neglecting to use the safeguard you have supplied; but these dreadful accidents even, if possible, exalt its importance.
"If your fame had needed any thing to make it immortal, this discovery alone would have carried it down to future ages, and connected it with benefits and blessings.
"Receive, Sir Humphry, this permanent memorial of our profound respect and high admiration—a testimony, we trust, equally honourable to you and to us. We hope you will have as much pleasure in receiving, as we feel in offering it. Long may you live to use it—long may you live to pursue your splendid career of scientific discovery, and to give new claims to the gratitude and praise of the world!" Sir Humphry having received the plate, replied as follows:
"Gentlemen,—I feel it impossible to reply, in an appropriate manner, to the very eloquent and flattering address of your distinguished Chairman. Eloquence, or even accuracy of language, is incompatible with strong feeling; and on an occasion like the present, you will give me credit for no small degree of emotion.
"I have been informed that my labours have been useful to an important branch of human industry connected with our arts, our manufactures, commerce, and national wealth. To learn this from such practical authority is the highest gratification to a person whose ardent desire has always been to apply science to purposes of utility.
"It has been also stated, that the invention which you are this day so highly honouring, has been subservient to the preservation of the lives and persons of a most useful and laborious class of men: this, coming from your own knowledge, founded upon such ample experience, affords me a pleasure still more exalted—for the highest ambition of my life has been to deserve the name of a friend to humanity.
"To crown all, you have, as it were, embodied these sentiments in a permanent and magnificent memorial of your good opinion. I can make only imperfect and inadequate efforts to thank you.
"Under all circumstances of my future life, the recollection of this day will warm my heart; and this noble expression of your kindness will awaken my gratitude to the latest moment of my existence."
Sir Humphry having sat down, and the cheering of the company subsided, the Chairman proposed the health of the illustrious Chemist, in three times three.
"Gentlemen," said Sir Humphry, "I am overpowered by these reiterated proofs of your approbation. You have overrated my merits. My success in your cause must be attributed to my having followed the path of experiment and induction discovered by philosophers who have preceded me: willingly would I divide your plaudits with other men of science, and claim much for the general glory of scientific discovery in a long course of ages.
"Gentlemen, I might dwell at some length upon the great increase of wealth and power to the country, within the last half century, by scientific invention, which never could have existed without coal-mines:—I shall refer only to the improvement in the potteries, to the steam-engine, and to the discovery of the gas lights.
"What an immense impulse has the steam-engine given to the arts and manufactures! How much has it diminished labour, and increased the real strength of the country, far beyond a mere increase of population! By giving facilities to a number of other inventions, it has produced even a moral effect in rendering capital necessary for the perfection of labour, credit essential to capital, and ingenuity and mental energy a secure and dignified species of property.
"Science, Gentlemen, is of infinitely more importance to a state than may at first sight appear possible; for no source of wealth and power can be entirely independent of it; and no class of men are so well able to appreciate its advantages as that to which I am now addressing myself. You have not only derived from it the means of raising your subterraneous wealth, but those also of rendering it available to the public.
"Science alone has made pit-coal such an instrument in the hands of the chemist and mechanic; it has made the elements of fire and water perform operations which formerly demanded human labour, and it has converted the productions of the earth into a thousand new forms of use and beauty.
"Gentlemen, allow me to observe, in conclusion, that it was in pursuing those methods of analogy and experiment, by which mystery had become science, that I was fortunately led to the invention of the Safety-lamp. The whole progress of my researches has been registered in the Transactions of the Royal Society, in papers which that illustrious body has honoured by their biennial medal;[47] in which I can conscientiously assert, that I have gratefully acknowledged even the slightest hints or offers of assistance which I have received during their composition.
"I state this, Gentlemen, not from vain-glory, but on account of certain calumnious insinuations which have arisen—not in the scientific world, for to that the whole progress of my researches is well known, but in a colliery. I must ever treat these insinuations with contempt; and after the honest indignation which has been expressed against them by the Coal-owners in general, I cannot feel any anxiety on the subject, nor should I have referred to it at all, did I not believe that the very persons amongst whom these insinuations originated, were extensively benefited by, and were constantly using the invention they would seek to disparage. I could never have expected that such persons would have engaged their respectable connexions in mean attempts to impeach the originality of a discovery, given to them in the most disinterested manner, and for which no return was required but an honest acknowledgment of the benefit, founded upon truth and justice.
"I do not envy them their feelings, particularly at the present moment: I do not wish to enquire into their motives: I do hope, however, that their conduct has been prompted by ignorance rather than by malevolence, by misapprehension rather than by ingratitude.
"It was a new circumstance to me, that attempts to preserve human life, and to prevent human misery, should create hostile feelings in persons who professed to have similar objects in view.
"Gentlemen, I have had some opposition, much labour, and more anxiety, during the course of these researches; but had the opposition, the labour, and the anxiety been a thousand times as great, the events of this day would have been more than a compensation."
Sir Humphry, after drinking the health and happiness of the company, proposed as a sentiment—"Prosperity to the Coal-trade."
The healths of the Duke of Northumberland, the Bishop of Durham, and the Reverend Dr. Gray, were drunk in succession.
At ten o'clock, Sir Humphry, accompanied by the chairman, retired amidst the enthusiastic plaudits of a meeting, the object of which being one of convivial benevolence, the effect was that of unclouded hilarity.
The party which had supported the claims of Mr. Stephenson had also their meeting; and it was held on the 1st of November. At this meeting it was resolved," That it was the opinion of the persons present, that Mr. G. Stephenson having discovered the fact, that explosions of hydrogen gas will not pass through tubes and apertures of small dimensions, and having been the first to apply the principle to the construction of a Safety-lamp, is entitled to some reward."
A committee was accordingly formed to carry this resolution into effect, at the head of which was placed the name of the Earl of Strathmore.
The respectable body of Coal-owners, under whose auspices the invention of Sir Humphry Davy had been introduced and rewarded, felt that they owed it to their own characters to repel assertions which amounted to a charge against themselves of ingratitude and injustice: a general meeting was accordingly summoned, at the Assembly-rooms in Newcastle, on the 26th of November 1817, J. G. Lambton, Esq. M.P. in the chair—when it was resolved,
"That the Resolutions passed at the Meeting of the friends of Mr. G. Stephenson on the 5th instant, impugn the justice and propriety of the proceedings of a meeting of the Coal-trade on the 31st of August 1816:
"That the present meeting, therefore, feel themselves called upon, as an act of justice to the character of their great and disinterested benefactor, Sir Humphry Davy, and as a proof that the Coal-trade of the North in no way sanctions the resolutions of Mr. Stephenson's friends, to state their decided conviction, that the merit of having discovered the fact, that explosions of fire-damp will not pass through tubes and apertures of small dimensions, and of having applied that principle to the construction of a Safety-lamp, belongs to Sir Humphry Davy alone.
"That this meeting is also decidedly of opinion, from the evidence produced in various publications by Mr. George Stephenson and his friends, subsequently to the meeting of the Coal-trade which was held on the 18th of March 1816, as well as from the documents which have been read at this meeting, that Mr. Stephenson did not discover the fact, that explosions of fire-damp will not pass through tubes and apertures of small dimensions; and that he did not apply that principle to the construction of a Safety-lamp; and that the latest lamps made by Mr. Stephenson are evident imitations of those of Sir Humphry Davy, and that, even with that advantage, they are so imperfectly constructed as to be actually unsafe.
"That the above resolutions be published thrice in the Newcastle papers, and in the Courier, Morning Chronicle, and Edinburgh Courant; and that printed copies thereof be sent to the Lords Lieutenants of the two counties, to the Lord Bishop of Durham, and to the principal owners and lessors of collieries upon the Tyne and Wear."
The following letter from Sir Humphry Davy announces the farther measures which he also had thought proper to pursue, in order to counteract the impression which the meeting of Mr. Stephenson's friends might have produced on the less informed part of the public.
TO J. G. LAMBTON, ESQ. M.P.
November 21, 1817.
MY DEAR SIR,
I shall send off by this post a copy of the resolutions, which will appear to-morrow in the Chronicle and Courier.
The men of science who have signed these resolutions are the first chemists and natural philosophers of the country, with the President of the Royal Society, the most illustrious body in Europe, at their head.
It is disagreeable to be thus obliged to use artillery for the destruction of bats and owls; but it was necessary that something should be done.
The Messrs. —— have for a long time been endeavouring to destroy my peace of mind; my offence being that of conferring a benefit.
The only persons I knew in Newcastle, before I gave the Safety-lamp to the Coal-owners, were Dr. Headlam and Mr. Bigge, so that friends I had none; and the few persons with whom I had a slight acquaintance, and who were civil to me before I discovered the Safety-lamp, became my enemies. It requires a deep metaphysician to explain this—Can it be that I did not make them the medium of communication to the colliers?—But I quit a subject to which I have no desire to return, and shall only recollect that day when your eloquence touched my feelings more than it flattered my self-love.
Believe me, &c. &c.
H. Davy.
The following are the Resolutions of a Meeting adverted to in the preceding letter, and which was held "for considering the Facts relating to the Discovery of the Lamp of Safety."
Soho Square, Nov. 20, 1817.
"An advertisement having been inserted in the Newcastle Courant, of Saturday, November 7, 1817, purporting to contain the Resolutions of 'A Meeting held for the purpose of remunerating Mr. George Stephenson, for the valuable service he has rendered mankind by the invention of his Safety-lamp, which is calculated for the preservation of human life in situations of the greatest danger,'
"We have considered the evidence produced in various publications by Mr. Stephenson and his friends, in support of his claims; and having examined his lamps, and enquired into their effects in explosive mixtures, are clearly of opinion—
"First,—That Mr. George Stephenson is not the author of the discovery of the fact, that an explosion of inflammable gas will not pass through tubes and apertures of small dimensions.
"Secondly,—That Mr. George Stephenson was not the first to apply that principle to the construction of a Safety-lamp, none of the lamps which he made in the year 1815 having been safe, and there being no evidence even of their having been made upon that principle.
"Thirdly,—That Sir Humphry Davy not only discovered, independently of all others, and without any knowledge of the unpublished experiments of the late Mr. Tennant on Flame, the principle of the non-communication of explosions through small apertures, but that he has also the sole merit of having first applied it to the very important purpose of a Safety-lamp, which has evidently been imitated in the latest lamps of Mr. George Stephenson.
(Signed)"Joseph Banks, P.R.S.
"William Thomas Brande,
"Charles Hatchett,
"William Hyde Wollaston."
Thus terminated a controversy, the discussion of which, I am well aware, many of my readers will consider as having been protracted to a tedious, and perhaps to an unnecessary extent; but the biographer had no alternative. In passing it by without a notice, he would have violated his faith to the public, have given a tacit acknowledgment of the claims of Stephenson, and, in his judgment, have committed an act of gross injustice to the illustrious subject of his history; while by giving only an abridged statement, he would have furnished a pretext for doubt, and an opportunity for malevolence.
It is due also to Sir Humphry Davy to observe, that had he practised more reserve in the communication of his results, the spirit of rivalry would have expired without a struggle,—for it derived its only support and power from the generosity of its victim. Had he secured for himself the advantages of his invention by patent, he might have realized wealth to almost any extent; but to barter the products of his intellectual exertions for pecuniary profit, was a course wholly at variance with every feeling of Davy's mind; and we therefore find him, in the advancement, as at the commencement of his fleeting career, spurning the golden apples from his feet, and hastening to the goal for that prize which could alone reward all his labours—the meed of immortal fame.
From a letter dated Newcastle, August 1830, which I had the pleasure to receive from Mr. Buddle, I extract the following interesting passage:—
"In the autumn of 1815, Sir Humphry Davy accompanied me into some of our fiery mines, to prove the efficacy of his lamp. Nothing could be more gratifying than the result of those experiments, as they inspired every body with perfect confidence in the security which his invention had afforded.
"Sir Humphry was delighted, and I was overpowered with feelings of gratitude to that great genius which had produced it.
"I felt, however, that he did not contemplate any pecuniary reward; and, in a private conversation, I remonstrated with him on the subject. I said, 'You might as well have secured this invention by a patent, and received your five or ten thousand a-year from it.' The reply of this great and noble-minded man was,—'No, my good friend, I never thought of such a thing; my sole object was to serve the cause of humanity; and, if I have succeeded, I am amply rewarded in the gratifying reflection of having done so.' I expostulated, saying, that his ideas were much too philosophic and refined for the occasion. He replied, 'I have enough for all my views and purposes; more wealth might be troublesome, and distract my attention from those pursuits in which I delight;—more wealth,' he added, 'could not increase either my fame or my happiness. It might, undoubtedly, enable me to put four horses to my carriage; but what would it avail me to have it said that Sir Humphry drives his carriage-and-four?'"
The present Bishop of Bristol, to whom the world is so greatly indebted for having first called the attention of Sir Humphry Davy to the subject of explosions from fire-damp, and who has kindly interested himself in my arduous and anxious undertaking, was desirous to obtain for me the latest accounts with respect to the Safety-lamp, as to the constancy of its use, and the extent of its security; and his Lordship informs me, that having applied to Mr. Buddle and Mr. Fenwick for information upon these points, their answers have been most satisfactory; at the same time, his Lordship transmitted me much valuable information, which was accompanied by the following letter from Mr. Buddle.
TO THE RIGHT REVEREND THE LORD BISHOP
OF BRISTOL.
Wall's-End, August 11, 1830.
MY LORD,
I have the honour to acknowledge the receipt of your Lordship's letter of yesterday's date. I am glad your Lordship has interested yourself in Doctor Paris's work, and I hope that he will be enabled, through the assistance of Sir Humphry's friends, to do ample justice to the genius and worth of that excellent man.
I should be very happy if any letters of mine could assist Dr. Paris in doing justice to his merits in the invention of the Safety-lamp; and I shall with pleasure submit to your Lordship's better judgment and discretion the selection of such of them as may seem to be conducive to that object.
I do not find that any improvement whatever has been made, either in the principle or construction of the original lamp, as presented to us by Sir Humphry. His transcendent genius seems to have anticipated every thing belonging to the subject, and has left nothing more to be done.
I have the honour to be,
My Lord, with great respect,
Your Lordship's most obedient,
Humble servant,
John Buddle.
In consequence of some late reports of accidents in the mines, I requested my friend Sir Cuthbert Sharp to make certain enquiries in the mining districts; and for this purpose, I sent him a string of queries, to which I begged him to obtain answers. These questions were submitted to Mr. Buddle, and they produced the following letter.
TO SIR CUTHBERT SHARP.
Newcastle, August 28, 1830.
MY DEAR SIR CUTHBERT,
I return Dr. Paris's letter, and shall briefly answer his enquiries.
If the Davy lamp was exclusively used, and due care taken in its management, it is certain that few accidents would occur in our coal mines; but the exclusive use of the "Davy" is not compatible with the working of many of our mines, in consequence of their not being workable without the aid of gunpowder.
In such mines, where every collier must necessarily fire, on the average, two shots a-day, we are exposed to the risk of explosion from the ignition of the gunpowder, even if no naked lights were used in carrying on the ordinary operations of the mine.
This was the case in Jarrow Colliery, at the time the late accident happened. As the use of gunpowder was indispensable, naked lights were generally used, and the accident was occasioned by a 'bag' of inflammable air forcing out a large block of coal, in the face of a drift, from a fissure in which it had been pent up, perhaps from the Creation, and firing at the first naked light with which it came in contact, after having been diluted down to the combustible point by a due admixture of atmospheric air.
As to the number of old collieries and old workings which have been renovated, and as to the quantity of coal which has been, and will be saved to the public by the invention of the "Davy," it is scarcely possible to give an account, or to form an estimate.
In this part of the country, 'Walker's Colliery,' after having been completely worked out, according to the former system, with candles and steel-mills, and after having been abandoned in 1811, was reopened in 1818 by the aid of the "Davy" and has been worked on an extensive scale ever since, and may continue to be worked for an almost indefinite period.
Great part of the formerly relinquished workings of Wall's-end, Willington, Percy-main, Hebburn, Jarrow, Elswick, Benwell, &c. &c., as well as several collieries on the Wear, have been recovered, and are continued in work by the invention of the "Davy."
If I had only what you know perfectly well I have not—Time, I could write a volume on this subject.
I shall shortly, through the medium of a friend, get an important paper on the subject of the "Davy," put into Dr. Paris's hands.
Believe me, my dear Sir Cuthbert,
To remain yours very faithfully,
John Buddle.
The Bishop of Bristol has placed at my disposal a communication from Mr. Fenwick, a gentleman of much practical ability, which affords additional evidence of the utility of the lamp; from which the following is an extract.
"Sir H. Davy's safety-lamp has afforded much security in the general working of mines, particularly by enabling the coal-owner to work, in several situations, the pillars of coal formerly left therein, which, under the system of working by candles, or open flame, was deemed hazardous and impracticable; and, in consequence, one-sixth part more of coal may be estimated as obtainable from those mines which are subject to hydrogen gas. Also in the working of the pillars of coal, (commonly called the second working,) great advantages and securities, as well as saving of expenses, have resulted from the use of this lamp, not only to the lessees of collieries, inasmuch as more coal is obtained from a given space than before, (particularly in collieries subject to fire-damp,) but also to the lessor of such mines, by their being more productive, and of course more durable than heretofore.
"Another advantage results from the use of this Safety-lamp, and in the working of the pillars in particular. It is found now, through experience, that the changeable state of the atmosphere, which our barometers daily indicate, has a most powerful effect on the noxious air in mines; as, from a sudden change in the atmosphere, indicated by the rapid fall of the mercury in the barometrical tube, a rapid discharge of noxious gas into the workings and excavations of the mine is the consequence, caused by the want of the atmospheric equilibrium:[48] in which case the mine becomes suddenly surcharged with hydrogen, and if worked by the light of open flame, an explosion may take place before the possibility of such a circumstance can even be suspected; but if worked by the Safety-lamp, it is only shown by the gas in the lamp becoming a pillar of harmless flame. This circumstance frequently takes place when any atmospheric change causes the mercury in the barometer to sink to twenty-eight inches and a half or thereabouts."
In the year 1825, Sir Humphry Davy had the honour to receive from the Emperor Alexander of Russia, a superb silver gilt vase, standing in a circular tray enriched with medallions. On the cover was a figure, of about sixteen or eighteen inches in height, representing the God of Fire, weeping over his extinguished torch.
The circumstances under which this vase was presented have been communicated to me by Mr. Smirnove, Secretary to the Embassy.
TO J. A. PARIS, M.D.
Wigmore Street, May 29, 1830.
DEAR SIR,
It was in the month of April, or May, 1815, that the late Sir Humphry Davy expressed to Prince, then Count, Lieven, his wish to offer to the Emperor of Russia a model of his Safety-lamp, which he had recently improved, accompanied by an explanatory pamphlet on the subject.
Prince Lieven of course complied with this request; and the Emperor having been pleased to accept it, ordered the Ambassador, in November of the same year, to thank Sir Humphry for it in his Majesty's name, and to assure him how much his Majesty appreciated the merit of an invention, the double effect of which was to favour the progress of more than one branch of industry, and to ensure the safety of persons employed in the coal-mines, against those fatal accidents which had hitherto so frequently occurred. The Ambassador, at the same time, delivered to Sir Humphry a silver-gilt Vase,[49] in the name of the Emperor, in testimony of the high satisfaction with which that sovereign had been pleased to accept the object in question. I beg you to believe me, with regard and esteem,
Your faithful servant,
John Smirnove.
It is well known to the friends of Davy, that in his conversation as well as in his correspondence, he always dwelt with peculiar satisfaction and delight upon the invention of his Safety-lamp.
Mr. Poole, in a letter lately addressed to me, observes—"How often have I heard him express the satisfaction which this discovery had given him. 'I value it,' said he, 'more than any thing I ever did. It was the result of a great deal of investigation and labour; but, if my directions be only attended to, it will save the lives of thousands of poor labourers. I was never more affected,' he added, 'than by a written address which I received from the working colliers, when I was in the North, thanking me, in behalf of themselves and their families, for the preservation of their lives.' I remember how delighted he was when he showed me the service of plate presented to him by those very men and their employers, as a testimony of their gratitude."
The following letter evinces a similar feeling.
TO THOMAS POOLE, ESQ.
Queen's Square, Bath, Oct. 29, 1816.
MY DEAR POOLE,
It is very long since any letters have passed between us. The affections and recollections of friendly intercourse are of a very adhesive nature; and I think you will not be displeased at being put in mind that there is an old friend not very far from you, who will be very glad to see you.
Bath does not suit me much, nor should I remain here, but my wife has been indisposed, and the waters seem to benefit her, and promise to render her permanent service, and if that happens, I shall be pleased even with this uninteresting city.
I have seen many countries and nations since we met.
I have just come from the North of England, where it has pleased Providence to make me an instrument for preserving the lives of some of my fellow-creatures. You, I know, are of that complexion of mind that the civic crown will please you more than even the victor's laurel wreath.
I have a bed, though a small one, at your service; if you can come here for two or three days, I assure you we shall be most happy to see you. We shall remain in Bath about three weeks. I shall be absent for a few days in the beginning of next week, and after that I shall be stationary till the middle of November. Give me a few lines, and say when we may expect you.
I am, my dear Poole, very sincerely yours,
H. Davy.
TO THE SAME.
Grosvenor Street, Dec. 3, 1817.
MY DEAR POOLE,
The late melancholy event[50] has thrown a gloom over London, and indeed over England. The public feeling is highly creditable to the moral tone of the people.
The loss of a Princess, known only by good qualities, living in a pure and happy state of domestic peace, is in itself affecting; but when it is recollected that two generations of sovereigns of the first people in the world have been lost at the same moment, the event becomes almost an awful one.
I go on always labouring in my vocation. I am now at work on a subject almost as interesting as the last which I undertook. It is too much to hope for the same success; at least I will deserve it.
When you come to town in the spring, which I trust you will do, I shall show you my service of plate. I do not think you will like it the less for the cause of the gift.
I am not sure whether I shall not take a run down to Nether Stowey and the west for a few days, if you encourage me with any hopes of the estate[51] and of woodcocks. You will fix my plans.
I shall be disengaged between the 15th and Christmas, and shall like to revisit Lymouth, and above all to shake you by the hand.
Lady D. is in better health than I have ever known her to possess. She begs her kind remembrances.
I am, my dear Poole, most affectionately yours,
H. Davy.
In a strictly scientific point of view, the most interesting results which have arisen out of the investigation for constructing a Safety-lamp, are perhaps those which have made us better acquainted with the true nature of flame, and the circumstances by which it is modified; and which have led to some practical views connected with the useful arts.
It is, I think, impossible to enter into the details of those curious investigations[52] which, under the title of "Some Researches on Flame," were communicated to the Royal Society, and read before that body on the 16th of January 1817, without being forcibly struck with the address by which Davy, in the first instance, brought abstract science to promote and extend practical knowledge; and then, as it were by a species of multiplied reflection, applied the new facts thus elicited for the farther extension of speculative truth; which in its wider range became again instrumental in disclosing a fresh store of useful facts. It may be said to have been the power of dexterously combining such methods which constituted the felicity of his genius; for, in general, each of them requires for its successful application a mind of quite a distinct order and construction. Mr. Babbage has very justly observed, that those intellectual qualifications which give birth to new principles or to new methods, are of quite a different order from those which are necessary for their practical application. Davy furnished the exception that was necessary to make good the rule.
He detects, in the first instance, the general principle of inflammable gas, in a state of combustion, being arrested in its progress by capillary tubes; he next applies it to the construction of a Safety-lamp, and then, by observing the phenomena which this lamp exhibits, is led to novel views respecting the nature and properties of flame.—I shall endeavour to offer a popular view of the curious and interesting truths disclosed by this latter research.
He had observed that, when the coal gas burnt in the iron cage, its colour was pale, and its light feeble; whereas the fact is rendered familiar to us all by the flame of the gas lights, that in the open air carburetted hydrogen burns with great brilliancy. Upon reflecting on the circumstances of the two species of combustion, he was led to believe that the cause of the superiority of the light in the latter case might be owing to a decomposition of a part of the gas towards the interior of the flame, where the air was in the smallest quantity; and that the consequent deposition of charcoal might first by its ignition, and afterwards by its combustion, contribute to this increase of light. A conjecture which he immediately verified by experiment.[53]
The intensity therefore of the light of flames depends principally upon the production and ignition of solid matter in combustion, so that heat and light are in this process independent phenomena.
These facts, Davy observes, appear to admit of many applications; in explaining, for instance, the appearance of different flames—in suggesting the means of increasing or diminishing their light, and in deducing from their characters a knowledge of the composition of their constituent parts.
The point of the inner blue flame of a candle or lamp urged by the blow-pipe, where the heat is the greatest and the light the least, is the point where the whole of the charcoal is burnt in its gaseous combinations, without previous ignition. The flames of phosphorus and of zinc in oxygen, and that of potassium in chlorine, afford examples of intensity of light depending upon the production of fixed solid matter in combustion; while on the contrary, the feebleness of the light of those flames, in which gaseous and volatile matter is alone produced, is well illustrated by those of hydrogen and sulphur in oxygen, or by that of phosphorus in chlorine.
From such facts, he is inclined to think that the luminous appearance of shooting stars and meteors cannot be owing to any inflammation of gas, but must depend upon the ignition of solid matter. Dr. Halley calculated the height of a meteor at ninety miles, and the great American meteor, which threw down showers of stones, was estimated at only seventeen miles high. The velocity of the motion of such bodies must in all cases be immensely great, and the heat thus produced by the compression of the most rarefied air, Davy thinks, must be sufficient to ignite the mass; and that all the phenomena may be explained by assuming that falling stars are small solid bodies moving round the earth in very eccentric orbits, which become ignited only when they pass with immense velocity through the upper regions of the atmosphere, and which, when they contain either combustible or elastic matter, throw out stones with explosion.
By the application of such a principle did he also infer the composition of a body from the character of its flame: thus, says he, Ether, during its combustion, would appear to indicate the presence of olefiant gas. Alcohol burns with a flame similar to that of a mixture of carbonic oxide and hydrogen; so that the first is probably a binary compound of olefiant gas and water, and the second of carbonic oxide and hydrogen.
When the proto-chloride of copper is introduced into the flame of a candle or lamp, it affords a peculiar dense and brilliant red light, tinged with green and blue towards the edges, which seems to depend upon the separation of the chlorine from the copper by the hydrogen, and the ignition and combustion of the solid copper and charcoal.
The acknowledged fact of the brightest flames yielding the least heat is easily reconciled, when we learn that the light depends upon fixed matter which carries off the heat. It is equally obvious, that by art we may, for practical purposes, easily modify these phenomena.
In the next place, having observed that wire-gauze cooled down flame beyond its combustible point, he was led to enquire into the nature of pure flame; and he readily demonstrated it to be gaseous matter heated so highly as to be luminous; and that the temperature necessary for such an effect was much greater than had been imagined, varying, however, in different cases. The flame of a common lamp he proved, by a very simple experiment, to exceed even the white heat of solid bodies, and which is easily shown by the simple fact of heating a piece of platinum wire over the chimney of an Argand lamp fed with spirit of wine; when it will be seen that air, which is not of sufficient temperature to appear luminous, is still sufficiently hot to impart a white heat to a solid body immersed in it.
The fact of different gaseous bodies requiring different degrees of heat to raise them into flame, was an inference immediately deducible from the phenomena of his safety gauze. A tissue of one hundred apertures to the square inch, made of wire of one-sixtieth, will, at common temperatures, intercept the flame of a spirit-lamp, but not that of hydrogen; and, when strongly heated, it will no longer arrest the flame of the spirit-lamp. A tissue which, when red-hot, will not interrupt the flame of hydrogen, will still intercept that of olefiant gas; and a heated tissue, which would communicate explosion from a mixture of olefiant gas and air, will stop an explosion of fire-damp. Fortunately for the success of the Safety-lamp, carburetted hydrogen requires so high a temperature to carry on its combustion, that even metal, when white-hot, is far below it; and hence red-hot gauze, in sufficient quantity, and of the proper degree of fineness, will abstract heat enough from the flame to extinguish it.
The discovery of the high temperature which is necessary for the maintenance of flame, suggested to the philosopher the reason of its extinction under various circumstances. He considers, that the common operation of blowing out a candle principally depends upon the cooling power of the current of air projected into the flame;[54] and he observes, that the hottest flames are those which are least easily blown out. He farther illustrated this subject by surrounding a very small flame with a ring of metal, which had the effect of cooling it so far as to extinguish it; but a ring of glass, of similar dimensions and diameter, being a less perfect conductor of heat, produced no such effect.
It had been long known that flame ceased to burn in highly rarefied air; but the degree of rarefaction necessary for this effect had been very differently stated. The cause of the phenomenon was generally supposed to depend upon a deficiency of oxygen.
In the commencement of his enquiry into this subject, Davy observed that the flame of hydrogen gas, the degree of rarefaction and the quantity of air being the same, burnt longer when it issued from a larger than a smaller jet,—a fact the very reverse of that which must have happened had the flame expired for want of oxygen; he moreover observed, that when the larger jet was used, the point of the glass tube became white-hot, and continued red-hot till the flame was extinguished: he therefore concluded, that the heat communicated to the gas by this tube was the cause of its protracted combustion, and that flame expired in rarefied air, not for want of nourishment from oxygen, but for want of heat, and that if its temperature could be preserved by some supplementary aid, the flame might be kept burning. The experiment by which he confirmed this theory was as beautiful as it was satisfactory.
He burnt a piece of camphor in a glass tube, under the receiver of an air-pump, so as to make the upper part of the tube red-hot; its inflammation was found to continue when the rarefaction was nine times; but by repeating the experiment in a metallic tube, which could not be so considerably heated by it, it ceased after the rarefaction exceeded six times.
It follows then that by artificially imparting heat,[55] bodies may be made to burn in a rarefied air, when under other circumstances they would be extinguished.
The following may be considered as an experimentum crucis, in proof of the fact that combustibility is neither increased nor diminished by rarefaction.
He introduced the flame of hydrogen, in which was inserted a platinum wire, into a receiver of rarefied air, and he found that, as long as the metal remained at a dull red-heat, the flame continued to burn: now it so happens that the temperature, at which platinum approaches a red-heat, is precisely that at which hydrogen inflames under the ordinary pressure of the atmosphere; whence it follows, that its combustibility is not altered by rarefaction.
The same law was found to apply to the flames of other bodies; those requiring the least heat for their combustion always sustaining the greater rarefaction without being extinguished.[56]
Hitherto he had only considered the effects of rarefaction, when produced by the diminution of pressure; he had next to investigate the phenomena of rarefaction when occasioned by expansion from heat.
The experiments of M. de Grotthus had apparently shown that rarefaction by heat destroys the combustibility of gaseous mixtures; those of Davy, however, proved that it enables them to explode at a lower temperature.
In the progress of this research, while passing mixtures of hydrogen and oxygen through heated tubes, the heat being still below redness, he observed that steam was formed without any combustion.
Here was a slow combination without combustion, as long since observed with respect to hydrogen and chlorine, and oxygen and metals; and he believes that such a phenomenon will happen at certain temperatures with most substances that unite by heat. On trying charcoal, he found that at a temperature which appeared to be a little above the boiling point of quicksilver, it converted oxygen pretty rapidly into carbonic acid, without any luminous appearance, and that, at a dull red-heat, the elements of olefiant gas combined in a similar manner with oxygen, slowly and without explosion.
It occurred to Davy, in the progress of these experiments, that, during this species of slow combination, although the increase of temperature might not be sufficient to render the gaseous matters luminous, or to produce flame, it might still be adequate to ignite solid matters exposed to them. It was while engaged in devising experiments to ascertain this fact, that he was accidentally led to the discovery of the continued ignition of platinum wire, during the slow combination of coal gas with atmospheric air; the circumstances of which have been already related, as well as the curious invention to which the application of the fact gave origin.[57]
For this and his preceding papers on the subjects of flame and combustion, the President and Council of the Royal Society adjudged to Sir Humphry Davy the gold and silver medals, on the donation of Count Rumford;[58] and never, I will venture say, did a society in awarding a prize more faithfully comply with the intentions of its founder.
On the completion of these laborious enquiries, it was thought expedient to give a wider circulation to their results than the publication of them in the Philosophical Transactions was calculated to afford; and Sir Humphry Davy was therefore induced to reprint his principal memoirs, so as to form an octavo volume,[59] which might be accessible to the practical parts of the community.
The enlightened friends of science very reasonably expected that a service of such importance to society as the invention of the Safety-lamp, would have commanded the gratitude of the State, and obtained for its author a high parliamentary reward; nor were there wanting zealous and disinterested persons to urge the claims of the Philosopher: but a Government which had bestowed a splendid pension upon the contriver of an engine[60] for the destruction of human life, refused to listen to any proposition for the reward of one who had invented a machine for its preservation. It is true that, in consideration of various scientific services, they tardily and inadequately acknowledged the claims of Davy, by bestowing upon him the dignity of Baronetcy[61]—a reward, it must be confessed, that neither displayed any regard to his condition, nor implied the just estimate of his merits. The measure of value, however, enables us to judge of the standard by which the State rates the various services to society; and deeply is it to be lamented that the disproportioned exaltation of military achievement, crowned with the highest honours, depresses respect for science, and raises a false and fruitless object of ambition.
The passion for arms is a relict of barbarity derived from the feudal ages; the progress of civilization, and the cultivation of the mind, should have led us to prefer intellectual to physical superiority, and to recognise in the successes of science the chief titles to honour. This reversal of the objects of importance can never be redressed until the aristocracy shall be possessed of a competent share of scientific knowledge, and instructed to appreciate its value. To effect such a change, the system of education so blindly and obstinately continued in our great public schools, must be altered; for minds exclusively applied to classical pursuits, and trained to recognise no other objects of liberal study, are indisposed and indeed disqualified for enquiries ministering to the arts of life, and arrogantly despised for their very connexion with utility. It is in the early ignorance of the rudiments of science that the after negligence of science has its source.
The instances in proof of the extent of the ignorance and indifference I have noted, and of their pernicious effects upon the most important interests of society, especially legislation, and the administration of justice, are abundant. In Parliament, how is a question of science treated? In our courts of law, and criminal investigation, it is lamentable to observe the frequent defeat of justice, arising from erroneous conception, or from the utter absence of the requisite knowledge. In the ordinary affairs of life, we see conspicuous, amongst the dupes of quackery and imposture, those whose stations should imply the best instruction, and whose conduct, unfortunately, has the effect of example.
A contempt far-spreading, and proceeding from the well-springs of truth, is rapidly rising against this exalted ignorance; the industrious classes of society are daily becoming more imbued with knowledge upon scientific subjects, and the nobility, if they would preserve their superiority in social consideration, must descend to the popular improvement.
Before concluding the present chapter, I must carry back my history to the year 1815, for the purpose of recording a circumstance in the life of Davy, which, while it exemplifies his general love of science, evinces the local attachment he retained for the town of his birth.
In the year 1813, the Geological Society of Cornwall was established at Penzance. Its objects are to cultivate the sciences of Mineralogy and Geology, in a district better calculated perhaps for such pursuits than any other spot in Europe,—to register the new facts which are continually presenting themselves in the mines, and to place upon permanent record, the history of phenomena which had hitherto been entrusted to oral tradition; but, above all, its object was to bring science in alliance with art; to prevent the accidents which had so frequently occurred from explosion in the operation of blasting rocks; and, in short, to render all the resources of speculative truth subservient to the ends of practical improvement.
No sooner had the establishment of so useful an institution been communicated to Davy, than he testified his zeal for its welfare by a handsome donation to its funds; which was followed by a present of a very extensive suite of specimens, illustrative of the volcanic district of Naples, and which had been collected by himself. He also afterwards communicated to the Society a memoir on the Geology of Cornwall, which has been published in the first volume of its Transactions.
In this paper, he discusses several of the more difficult questions connected with the origin of veins.
He first observed the granitic veins, which have called forth so much attention from geologists, about the year 1797; probably before they had excited much scientific notice: he is disposed to regard them as peculiar to the low metalliferous granite and mica formations; he had seen several cases of granite veins near Dublin, in the Isle of Arran, and in other parts of Scotland; he had also observed several instances near Morlaix in Brittany, but he had in vain searched for them in the points of junction of the schist and granite, both in the Maritime, Savoy, Swiss, and Tyrolese Alps, and likewise in the Oriental Pyrenees.
The serpentine district of Cornwall, he thinks, has not yet met with the attention it deserves. "I have seen no formation," says he, "in which the nature of serpentine is so distinctly displayed. The true constituent parts of this rock appear to be resplendent hornblende and felspar; it appears to differ from sienite only in the nature of the hornblende, and in the chemical composition of its parts, and in being intersected by numerous veins of steatite and calcareous spar."
The nature and origin of the veins of steatite in serpentine, he considers as offering a very curious subject for enquiry. "Were they originally crystallized," he asks, "and the result of chemical deposition? or have they been, as for the most part they are now found, mere mechanical deposits?" He is inclined to the latter opinion. The felspar in serpentine, he observes, is very liable to decomposition, probably from the action of carbonic acid and water on its alkaline, calcareous, and magnesian elements; and its parts washed down by water and deposited in the chasms of the rocks, he thinks would necessarily gain that kind of loose aggregation belonging to steatite.
He had some years before made a rude, comparative analysis of the felspar in serpentine, and of the soap-rock, when he found the same constituents in both of them, except that there was not any alkali or calcareous earth in the latter substance. It is very difficult to conceive, he says, that steatite was originally a crystallized substance which has been since decomposed; for, in that case, it ought to be found in its primitive state in veins which are excluded from the action of air and water; whereas it is easy to account for the hardness of some species of steatite on the former hypothesis; for mere mechanical deposits, when very finely divided, and very slowly made, adhere with a very considerable degree of force. A remarkable instance of this kind occurred to him amongst the chemical preparations of the late Mr. Cavendish, which, on the decease of that illustrious philosopher, had been presented to him by Lord George Cavendish: there was a bottle which had originally contained a solution of silica by potash; the cork, during the lapse of years, had become decayed, and the carbonic acid of the atmosphere had gradually precipitated the earth, so that it was found in a state of solid cohesion; the upper part was as soft as the steatite, but the lower portion was extremely hard, was broken with some difficulty, and presented an appearance similar to that of chalcedony.
In speaking generally of the mineralogical interest of Cornwall, he observes, that "it may be regarded, κατ' εξοχην, as the country of veins; and that it is in veins that the most useful as well as the most valuable minerals generally exist, that the pure specimens are found which serve to determine the mineralogical species, and that the appearances seem most interesting in their connexion with geological theory. Thus veins, which now may be considered in the light of the most valuable cabinets of nature, were once her most active laboratories; and they are equally important to the practical miner, and to the mineralogical philosopher."
With regard to the general conformation of Cornwall, he states it to be in the highest degree curious, and he considers that the facts which it offers are illustrative of many important points of geological theory. "It exhibits very extraordinary instances of rocks broken in almost every direction, but principally from east to west, and filled with veins again broken in, diversified by cross lines, and filled with other veins, and exhibiting marks of various successive phenomena of this kind.
"Respecting the agents that produced the chasms in the primary strata, and the power by which they were filled with stony and metallic matter, it would be easy to speculate, but very difficult to reason by legitimate philosophical induction."
In the concluding passage, however, he very freely admits his preference for the doctrine of fire.
"It is amongst extinct volcanoes, the surfaces of which have been removed by the action of air and water, and in which the interior parts of strata of lavas are exposed, that the most instructive examples of the operation of slow cooling upon heated masses are to be found. It is difficult to conceive that water could have been the solvent of the different granitic and porphyritic formations; for, in that case, some combinations of water with the pure earths ought to be found in them. Quartz ought to exist in a state of hydrate, and Wavellite, not Corundum, ought to be the state of alumina in granite.
"To suppose the primary rocks, in general, to have been produced by the slow cooling of a mass formed by the combustion of the metallic bases of the earths, appears to me the most reasonable hypothesis; yet aqueous agency must not be entirely excluded from our geological views. In many cases of crystallization, even in volcanic countries, this cause operates; thus in Ischia, siliceous tufas are formed from hot springs; and in the lake Albula, or the lake of Solfaterra, near Tivoli, crystals of calcareous spar and of sulphur separate from water impregnated with carbonic acid and hepatic gas; and large strata of calcareous rocks, formed evidently in late times by water impregnated with carbonic acid, exist in various parts of Europe. The Travertine marble (Marmor Tiburtinum) is a production of this kind; and it is of this species of stone that the Colosseum at Rome, and the cathedral of St. Peter, are built. It is likewise employed in the ancient temple of Pæstum, and it rivals in durability, if not in beauty, the primary marble of Paris and Carrara."