Lightning Conductors: Their History, Nature, and Mode of Application

by F.C.S. Richard Anderson

In France itself the thus awakened resistance to the setting-up of lightning conductors was strikingly shown by an incident which occurred at the town of St. Omer, not far from Calais. A manufacturer settled here, who had been in America, and there learnt to appreciate the usefulness of Franklin’s lightning conductors, had one made for his own house, and quietly fixed it to wall and roof. But the populace no sooner heard of it when there arose a public disturbance, and the iron rod was torn down by force. So far from repressing the rioters, the municipality of St. Omer, acting under priestly influence, forbade the manufacturer to erect another lightning conductor, on the ground that it was ‘against law and religion.’ Thereupon the bold manufacturer, a man of English descent, to try his right, appealed to the tribunals, and the judges at last, after protracted pleadings, not being able to discover any statutes against the fastening of metal rods to buildings, declared that the thing might be done, but with precautions. The lawyer who pleaded the case of the lightning conductors before the French tribunals at this momentous period was a very young man, quite unknown to fame at the time, but destined for a superabundance of it. His name was Robespierre.

Perhaps the violent opposition which the erection of lightning conductors—or ‘Franklin rods,’ as they were often called—met almost everywhere, would have proved more effective than it ultimately turned out, had not the great discoverer himself showed admirable temper in meeting his enemies, thus pouring oil upon the stormy waters. His calmness and confidence is admirably shown in a letter, dated July 2, 1768, addressed to Professor John Winthrop, of Cambridge, in answer to one in which astonishment was expressed at the ‘force of prejudice, even in an age of so much knowledge and free inquiry,’ of not placing lightning conductors upon all elevated buildings. Franklin—or he must now be called Dr. Franklin, having received the degrees of LL. D. and D. C. L. from the universities of St. Andrew’s, Edinburgh, and Oxford—was residing in England at the time, as agent of the people of Pennsylvania. He was thoroughly acquainted with the state of public feeling, yet so far from being angry, smiled down upon it like a true philosopher. ‘It is perhaps not so extraordinary,’ he wrote to his friend, ‘that unlearned men, such as commonly compose our church vestries, should not yet be acquainted with, and sensible of, the benefits of metal conductors in averting the stroke of lightning, and preserving our houses from its violent effects, or that they should still be prejudiced against the use of such conductors, when we see how long even philosophers, men of science and of great ingenuity, can hold out against the evidence of new knowledge that does not square with their preconceptions; and how long men can retain a practice that is conformable to their prejudices, and expect a benefit from such practice, though constant experience shows its inutility. A late piece of the Abbé Nollet, printed last year in the Memoirs of the French Academy of Sciences, affords strong instances of this; for though the very relations he gives of the effects of lightning in several churches and other buildings show clearly that it was conducted from one part to another by wires, gildings, and other pieces of metal that were within, or connected with the building, yet in the same paper he objects to the providing of metallic conductors without the building, as useless or dangerous. He cautions people not to ring the church bells during a thunderstorm, lest the lightning, in its way to the earth, should be conducted down to them by the bell ropes, which are but bad conductors; and yet he is against fixing metal rods on the outside of the steeple, which are known to be much better conductors, and through which lightning would certainly choose to pass, rather than through dry hemp. And though, for a thousand years past, church bells have been solemnly consecrated by the Romish Church, in expectation that the sound of such blessed bells would drive away thunderstorms, and secure buildings from the stroke of lightning; and, during so long a period, it has not been found by experience, that places within the reach of such blessed sound are safer than others where it is never heard, but that, on the contrary, the lightning seems to strike steeples by choice, and at the very time the bells are ringing, yet still they continue to bless the new bells, and jangle the old ones whenever it thunders.’

‘One would think,’ continues Dr. Franklin, with exquisite humour, ‘that it was now time to try some other trick. Ours is recommended, whatever the able French philosopher may say to the contrary, by more than twelve years’ experience, during which, among the great number of houses furnished with iron rods in North America, not one so guarded has been materially hurt by lightning, and many have been evidently preserved by their means; while a number of houses, churches, barns, ships, &c., in different places, unprovided with rods, have been struck and greatly damaged, demolished, or burnt. Probably, the vestries of English churches are not generally well acquainted with these facts; otherwise, since as good Protestants they have no faith in the blessing of bells, they would be less excusable in not providing this other security for their respective churches, and for the good people that may happen to be assembled in them during a tempest, especially as these buildings, from their greater height, are more exposed to the stroke of lightning than our common dwellings.’

While Franklin thus wrote of ‘the great number of houses furnished with iron rods in North America,’ there was not a single public building so protected in England. Several private persons had adopted them for their houses, following the example of Dr. William Watson—subsequently Sir William—vice-president of the Royal Society, who had been the first to set up a lightning conductor in England, erecting one over his cottage at Payneshill, near London, in 1762. But notwithstanding the evident utility of the ‘Franklin rods,’ they were refused where they were most wanted—for larger buildings, and particularly for churches. The ‘unlearned men, such as commonly compose our church vestries,’ openly declared against them, and among the clergy there was a steady, if often silent, antagonism to their introduction. The first movement towards its being upset was given by an occurrence which caused much commotion, and gave rise to a vast amount of discussion. On Sunday, June 18, 1764, a few minutes before three in the afternoon, the splendid steeple of St. Bride’s Church, in the city of London, one of the architectural monuments of Sir Christopher Wren, was struck by lightning, the flash being intensely vivid, blinding several people. The damage done was so serious that about ninety feet of the steeple had to be taken down entirely, while great and expensive repairs were required for the rest. Dr. Watson, as the first introducer, so one of the chief promoters of Franklin’s invention in England, took this opportunity of publishing in the ‘Philosophical Transactions’ a detailed account of the effects of lightning upon St. Bride’s steeple, explaining the potency of conductors in the very action of the electric force. He showed how the lightning first struck the metallic weathercock at the top of the steeple, and ran down, without injuring anything, the large iron bars by which it was supported. At the bottom of the bars, the electric force shattered a number of huge stones into fragments, to make its way to some other pieces of iron, inserted into the walls to give them strength. So it went on till there were no more metals, when havoc and destruction became the greatest. Thus, as Dr. Watson conclusively proved, the beautiful steeple of St. Bride was wilfully made over to ruin for want of a few hundred yards of iron, or other metal, which would lead the electric force harmlessly from the weathercock on the summit into the earth. He finished by telling in the plainest terms, to all on whom devolved the duty of taking care of churches, that it was neglectful, even to criminality, not to protect them by conductors against the always imminent danger of being struck by lightning.

The lay-sermon of Dr. Watson, deeply impressive by the power of the indisputable facts on which it was based, had a considerable effect in rousing public opinion, finding its way even into the dull ears of ‘such as commonly compose church vestries.’ Among the most important results was a step taken, after long and solemn deliberations, extending over several years, by the Dean and Chapter of St. Paul’s. They made an application to the Royal Society, asking for advice as to the best means of protecting the great cathedral, Sir Christopher Wren’s noblest creation, against the perils of lightning. The application was made on March 22, 1769, as recorded under that date in the ‘Gentleman’s Magazine.’ ‘A letter from the Dean and Chapter of St. Paul’s,’ it was stated, ‘was read at the Royal Society, requesting the direction of that learned body for the sudden effects of lightning. It was referred to a committee consisting of Dr. Franklyn (sic), Dr. Watson, Mr. Canton, Mr. Edward Delaval, and Mr. Wilson, who, after having examined the building, are to report their opinion.’ The committee thus nominated embraced all the most eminent men of the day who had studied the phenomena of electricity, and in the order in which they ranked. Next to the great discoverer of the lightning conductor himself, Dr. Watson could claim to stand; and next to him Mr. John Canton, a most painstaking and intelligent worker in the field, inventor of the pith-ball electrometer, and other instruments.

But a curious element of discord pervaded from the first this small conclave of learned men, chosen to decide the not unimportant question as to the best means of providing the cathedral of St. Paul with lightning conductors. That the noble building should be so protected, all were agreed; and it was clearly understood, besides, that if once St. Paul’s had lightning conductors, all the other cathedrals and principal churches of England would follow suit. What they differed upon was not this, but the best form of lightning conductors. Franklin’s steadfast assertion that points to the elevated rods were not only far preferable to any other form of conductors, but the only really protective ones, was adopted by Dr. Watson and Mr. Canton; but they were opposed by Mr. Wilson, who asserted, with some degree of vehemence, that points were dangerous, and that balls on the summit of the rods afforded infinitely better protection. Standing alone in this view among the eminent members of the committee of the Royal Society, his arguments naturally had no effect, and the recommendation to the Dean and Chapter of St. Paul’s was to protect the cathedral by pointed lightning conductors. This was done accordingly. ‘Franklin rods’ were attached to Wren’s splendid structure, worthy to be the introducer of them, on a large scale, in Europe.

The dispute as to pointed conductors, or balls, was by no means brought to a termination by the decision that was come to regarding St. Paul’s. Endless pamphlets were published on the subject, and it went so far as to being turned into a political question. As priests scented heresy in the daring attempt to draw lightning from the clouds, so the court faction and ultra-conservatives of England smelt republicanism in the erection of iron rods designed by the representative of the disaffected American colonies. The king was understood to have given his own high opinion entirely against points, and in favour of balls, declaring his preference by ordering a cannon ball of large size to be placed on the top of a conductor erected over the royal palace at Kew. Meeting such high patronage, the ‘anti-Franklinians’ only sought an occasion to break out into open scientific warfare, and they were not long in finding it. On May 15, 1777, a large public building at Purfleet, on the Thames, serving as a storehouse for war material, was struck and greatly damaged by lightning, although protected by a pointed lightning conductor. Thereupon arose an instant outcry against the system advocated by Dr. Franklin. From much evidence adduced, there could be no doubt that the building at Purfleet had been hurt simply because the conductor was defective in parts, and was besides not laid deep enough into the ground; still this did not stop the clamour raised. Chiefly through the agitation of Mr. Wilson, the members of the Royal Society entered into hot discussions about the respective merits of pointed and round conductors. The feeling of the partisans of the latter side ran so high on this occasion, that Sir John Pringle had to resign the presidency of the Royal Society, which post he had ably filled since 1772, for making himself an advocate of points against balls. When the fever of the learned men had cooled down a little, it was resolved to settle the great question of points versus balls by a series of experiments, to be held in the Pantheon, a large building in Oxford Street, dome-like in the interior. The arrangement, in fact, carried out under the direction of Mr. Wilson, leader of the ‘ball’ party, was to create an artificial thunderstorm—or, as it should properly be called, ‘lightning storm’—by means of powerful electrical batteries, to be discharged upon conductors of various forms. His Majesty George III., greatly interested in the subject, and cherishing fond hopes that cannon-balls would carry off the victory in the scientific dispute, as well as in the graver political one with Franklin’s countrymen, undertook to pay all the expenses of the Pantheon experiments, and they took place accordingly on an elaborate scale. But though prepared entirely with a view of showing the inefficiency of Dr. Franklin’s points, they proved absolutely the contrary. Artificial, like real, lightning clearly showed its preference for a lancet over a ball; it would glide down the former quietly, but fall heavily, mostly with an explosion, upon the latter. However, the question being in reality less a scientific controversy than a dispute arising from the fiery heat of political passions, it was by no means set at rest by the Pantheon trials. ‘Franklin rods’ were more than ever abhorred by a multitude of persons, learned and unlearned, after the great citizen of Philadelphia had set his hand, on July 4, 1776, to the declaration of independence of the ‘United States of America,’ and more than a quarter of a century had to elapse, a new generation of men growing up, before there arose clear and unimpassioned views about lightning conductors.

While thus the battle of the rods was being fought in England, it raged no less hotly on the continent of Europe. Here there was religious prejudice alone at work, the political sympathies running in favour of anything coming from America. But priestly animosity by itself proved as strong an obstacle as any other to the erection of lightning conductors. Where it did not exist, they sprang up with rapidity; but wherever its influence was felt, the movement was arrested. In the most enlightened parts of Germany, the seat and home of Protestantism, the ‘Franklin rods’ early made their appearance. The first lightning conductor set up over a public building in Europe was erected early in 1769 on the steeple of the church of St. Jacob, Hamburg; and so rapid was the spread of them that, at the end of five years from this date, there were estimated to be over seven hundred conductors within a circle of ten miles of the old Hanse town. To this day they are comparatively more numerous in this district than anywhere else in Europe. In contrast with Northern Protestant Germany, the Roman Catholic South refused the ‘Franklin rods,’ and so did France, although making a hero of Franklin personally. For many years after young Robespierre pleaded the case of lightning conductors before the tribunal of St. Omer, the strongest abhorrence to them was expressed by the priests and their mob following in almost all parts of France, and the active antagonism did not cease till after the outbreak of the great revolution.

It was the same in most countries of southern and central Europe. Even in Geneva, famous for the enlightenment of its citizens, the populace made an attempt to pull down the first lightning conductor. It was erected, in the summer of 1771, by the celebrated naturalist, Professor Horace de Saussure, over his own house, after directions furnished by Dr. Franklin. But notwithstanding that the professor was himself highly respected, his lightning conductor created general abhorrence, and to appease it he found it necessary to issue a public address or ‘manifesto,’ as he called it, to his fellow-citizens. The address, dated November 21, 1771, was strangely characteristic of the times. ‘I hear with regret,’ Professor de Saussure declared, ‘that the conductor which I have placed over my house to protect it against lightning, as well as to observe, occasionally, the electricity of the clouds, has spread terror among many persons, who seem to fear that by this means I draw upon the heads of others those dangers from which I myself wish to escape. Now, I beg you to believe that I would never have decided upon erecting this apparatus, if I had not been fully persuaded both of its harmlessness and its utility. There is no possibility of its causing damage to my own house, or of doing harm to others. All those who are now labouring under fear would be precisely of the same opinion, if they had entered upon the same inquiries to which I am called in the course of my studies.’ After which the professor goes on minutely to describe the ‘electric conductor,’ which he had been bold enough to place over his house, dwelling upon the fact of its having protected, as he believed, already his own residence from being struck by lightning, and of having been found, likewise, universally efficacious in the same manner in ‘the English colonies of North America.’ The citizens of Geneva, much given to reasoning, earnestly read and studied the ‘manifesto’ of Professor de Saussure, and the consequence was, not only that he was spared further attacks and reproaches, but that there arose soon over the churches and houses of the town some hundreds of lightning conductors.

In Italy the progress in the erection of conductors was accompanied by some very curious incidents. The priests here, as in other Roman Catholic countries, actively opposed their introduction, and to do so more effectively, they craftily attached to them a stinging name, calling them ‘heretical rods.’ As a consequence, the mob fiercely opposed the putting-up of any such accursed pieces of metal, and whenever the attempt was made to fasten them to houses, it met with forcible opposition. However, some of the highly accomplished professors of the universities of Italy, enthusiastic in their reception of Franklin’s discovery, proved themselves victorious over both priests and mob. They got the Grand Duke Leopold of Tuscany—subsequently German Emperor, under the title of Leopold I.—a man of high scientific acquirements, to place lightning conductors over his own palace, as well as over all the powder magazines in his dominions. Here the mob and priest rule ceased, and only silent curses could be levelled against the ‘heretical rods.’ Another still more important step in advance was made by the influence of the Abbé Giuseppe Toaldo, a warm admirer of Franklin, in correspondence with him, and author of various scientific works, among them one on lightning conductors. He had some influence with the ecclesiastical authorities at Siena, in Tuscany, and brought it to bear upon them by getting them to consent to make trial, in a manner so as not to excite public attention, of one of the ‘heretical rods,’ over the cathedral. This was only permitted on account of the extreme danger in which the edifice stood, having been struck several times by lightning, and greatly damaged. Placed on the summit of the highest of the three hills on which stands the ancient city of Siena, the cathedral was opposed to the dangers brought in the womb of every passing thunderstorm, and they were all the greater as the building, erected by Pisano in the thirteenth century, was deemed to be priceless, being one of the most magnificent structures of the kind in Italy, of red and white marble, filled with the choicest specimens of art, statues, pictures, gold and jewelry. It seemed well worth risking a little heresy to guard such treasures.