Asbestos, Its production and use / With some account of the asbestos mines of Canada

by Robert H. Jones

With regard to closing the breeches of big guns, we are informed also on the authority of Sir Frederick Abel, that the only contrivance which could be called an approach to a perfect arrangement, was one devised by a French artillery officer, M. Dubange, which consisted of a kind of pad of asbestos fibre attached to the breech-closing arrangement. This, from its mineral nature, was nearly indestructible, and, consequently, lasted without material deterioration for a great length of time, notwithstanding that it was subjected to the enormous pressures which are now developed in the bores of very heavy guns.

In connection with the Whitehead torpedoes, we learn from the same authority, that in these and other similar receptacles, within which charges of wet gun cotton are enclosed, the use of asbestos is now found to overcome a great difficulty. The vessels containing the damp cotton have to be soldered, in order to keep them perfectly air-tight, and thus prevent the water from escaping; and in order to do this, with anything approaching safety, the space between the gun cotton and the metal surfaces which have to be soldered, were formerly filled with damp felt wads or discs. This answered the purpose; but Sir Frederick Abel states that it was found after they had been stored for some time, that the effect of the moisture on the felt was to cause it to undergo a kind of decay or fermentation, resulting in the formation of gas to such an extent that the vessels were distended, and threatened to burst, and sometimes actually did burst with considerable violence. Asbestos millboard was then substituted for the felt, and the difficulty and danger were then removed; gas was no longer evolved, whilst the operation of soldering could be performed with safety, the material remaining perfectly unaltered.

In the manufacture of time-fuzes again, asbestos washers are found most valuable. Washers of india-rubber and wash-leather were formerly used, but these in time became hard, and acted on the metal surfaces with which they came in contact in such a manner as to cement them together, instead of keeping them mobile, and it was not until the introduction of asbestos washers that difficulties in connection with the proper action of these ingenious contrivances for the explosion of shells in a given time after their discharge, were removed.

One of the latest uses to which asbestos has been proposed to be applied in connection with warfare is as a coating for ironclads. It is alleged by the inventor of the process that if asbestos be packed between the armour-plates it will arrest, or certainly minimise, the inflow of water after the penetration of a ship's side below the water-line. This has already been tried by the Admiralty, and an interesting account of the trial may be found in the Army and Navy Gazette Supplement, for August 28, of last year, and in the Globe of the previous evening. Should the results of further trials corroborate the success of the first, it is manifest that a great impetus will be given to the asbestos trade, whilst it will, at the same time, raise confidence in our fighting ships, by practically preventing them from becoming waterlogged in action.

An eminent firm of manufacturers in New York have recently supplied, under contract with the United States Government, a quilting for boiler covers for their model warships, the Dolphin, Chicago, Atlantic, and Boston. These quiltings weigh about two pounds to the square foot, and are at all times removable. The same firm make removable pipe coverings a speciality.

Certainly some of the uses to which this mineral is now being put are sufficiently astonishing. Who, for instance, could have imagined that a substance of such comparative specific gravity as crude asbestos could have been manufactured into a cloth available for aeronautical purposes in which absence of weight is of such primary importance? Yet here it appears to be the one thing wanting to give success to that despair of aeronauts, military ballooning. Many years have now passed away since scientific military men first turned their attention to this subject; and it is now long since the War Department of the Government first authorized experiments to be made with the view of utilising balloons in warfare, and notwithstanding all the time and money which has been expended, until now the result in the way of practical success has been nil. No use of balloons was made even in the late Egyptian campaign, which shows that up to that date English military men had no great faith in their usefulness or availability.

The difficulties to be encountered are doubtless sufficiently formidable. Gas, it is clear, could not be carried into a hostile country or into remote and nearly inaccessible districts. Even if procurable at all near the battle-field it could only be obtained by a long and difficult process of generation at the very time when speed and simplicity would be the main factors of success. Gas, therefore, being practically out of the question, it seems to have occurred to Mr. Spencer, the well-known balloon manufacturer, that it would be better after all to revert to the original conception of Montgolfier. The old-fashioned fire-ball, which acquired its power of ascension from rarefied air produced by burning straw or something similar, was, of course, of far too dangerous a character, and had been productive of far too many fatal accidents. It remained, therefore, to construct a balloon of some uninflammable material, in order to obviate this difficulty; and with the assistance of his friend, Mr. Fisher, the Secretary of the United Asbestos Company of London, he ultimately succeeded in so doing. A balloon was accordingly constructed, the whole of the lower part of which was formed of fine asbestos cloth, and the remainder of canvas, covered with a fireproof solution. The first trial took place in the grounds of the Welsh Harp, at Hendon, and this has since been repeated at Chatham, under the inspection of the Royal Engineers' Committee, and on both occasions, I am informed, with success. The balloon, which was a model only, stood about 30 feet high, and was suspended between two uprights, between which it hung down like a limp rag. It was of a cylindrical shape, having a deep zone at the equator, and a containing capacity of about 300 feet. Attached to the neck was a copper spirit-lamp. As soon as a light was put to the spirit the inflation commenced, and the balloon was fully distended in a space of about five minutes.

The immense advantage gained by this method over the tedious and difficult process of inflation by gas, even under the most favourable circumstances, is sufficiently obvious, whilst it is at the same time apparent that the quantity of spirit requisite for an endless number of ascents could be carried about with the greatest facility. Another advantage remains to be considered, in that whilst the large volume of gas required for an ordinary balloon is in itself deleterious, the rarefied air in the new fireproof balloon is perfectly innocuous, and it can be raised or lowered at will simply by turning the neck of the lamp a little up or down. It is perhaps somewhat superfluous to say that the Russian Government at once adopted these balloons for war purposes.

In further continuance of this part of the subject, that is the application of asbestos to matters connected with warfare, the particulars of a very interesting experiment, which may have an important bearing on the carriage of explosive material in time of war, was given by Mr. Boyd, the manager of the United Asbestos Company's works at Harefield, of whom I have already spoken, and to whom I have been considerably indebted for much practical information, in a paper read by him before the Society of Arts, on an occasion when, through his kindness, I had an opportunity of being present. He was referring to the value of asbestos millboard as a lining for fireproof cases and deed boxes. The matter, he said, was put to a practical test thus: two iron rails were supported on brickwork at a height of about eighteen inches from the ground, and underneath them a strong fire of wood shavings and chips was made, and when this had well burnt up, a deed box filled with papers was pushed along the rails to the centre of the fire, where it was completely enveloped in the flames, and there it remained for a space of twenty minutes. On the box being withdrawn it unlocked easily, and the papers were found in perfect preservation, being neither charred nor discoloured.

On seeing this result, one of the gentlemen present asked if the boxes could not be used for transporting gunpowder or other explosive substances. A quarter of a pound of powder was then put in a small bag, and placed inside a fresh box, which was pushed along the rails into the centre of the fire, to which fresh fuel had been added. Those present withdrew to a respectful distance, evidently, said Mr. Boyd, not yet having absolute faith in the heat-resisting properties of asbestos; and after the box had been exposed to the fire for twenty minutes the question naturally arose how it was to be got off again. The manager himself performed that operation by means of a long iron rod and hook, after which the box was again opened and the powder found intact. The question was then asked by some one present who was not yet satisfied, "Why have the powder in a bag? Let it be laid on the bottom of the box loose." This was done, and the fire ordeal repeated, again with the same result. Nothing could well be more interesting or more suggestive to every one connected with the asbestos industry than the foregoing.