250 Mr. F. A, Abel, on the Application of Science [April 27, 



in this direction ; and, at the suggestion of the former, attempts were 

 made to employ the electricity obtained, by induction, from permanent 

 magnets. No difficulty was experienced in igniting a single charge 

 by its agency ; but it was found that the ignition of more than one 

 charge could not be effected with certainty, by the employment even 

 of the most powerful magnets and the use of fuses containing very 

 sensitive compositions. Eventually, a fuse-arrangement was contrived 

 and a composition prepared, by Mr. Abel, with the employment of 

 which the ignition of several mines could be effected with certainty, 

 by means of one of the small magnetic arrangements employed by Mr. 

 Wheatstone in iiis portable telegraphs ; and an ingenious combination 

 of several such magnets, arranged in a form very portable and readily 

 worked by any soldier, can be applied with equal certainty to the dis- 

 charge of a considerable number of mines. The great element of 

 success in the fuse-composition employed, is to be found in the circum- 

 stance that it combines a high degree of sensitiveness with considerable 

 conducting power. The substitution of the magnet for the voltaic and 

 other arrangements hitherto used will greatly facilitate mining opera- 

 tions ; the soldier requires but little instruction in its use ; with ordinary 

 care it is not liable to derangement ; it is very transportable, and ready 

 for application at the shortest notice. 



In connection with submarine operations, vulcanised india-rubber 

 bags have become valuable substitutes for the wooden and metal re- 

 ceptacles hitherto employed for the charges of powder. The numerous 

 applications which india-rubber, especially in its vulcanised form, now 

 receives in connection with military equipment, render it a most indis- 

 pensable material. Thus, it has been applied to the preparation of 

 waterproof linings for powder-barrels, waterproof cases for cartridges, 

 convenient holders and waterproof coatings for percussion caps ; it is 

 used in the form of springs and buffers in connection with gun-carriages 

 and the beds of heavy mortars ; ambulance waggons are supplied with 

 efficient and easily applicable springs of india-rubber ; and one of the 

 most important additions recently made to the comfort of troops has 

 been the general supply to them, when on active service, of waterproof 

 clothing and covers, to be used in camp. 



The protection of camp-erections from fire has also received atten- 

 tion with successful results. A cheap and ready mode of applying a 

 coating of insoluble silicate of lime and soda to the surfaces of camp- 

 huts, whereby very important protection against fire is attained, received 

 application a few years ago ; and quite recently a method has been 

 devised by Mr. Abel of impregnating tent-cloth with silicates, to such 

 an extent as effectually to prevent fire from spreading, when applied 

 to any portion of it, and in such a form as to enable them to resist the 

 solvent effect of drenching rains. 



The application of soluble silicates to the preparation of very 

 porous artificial stone has enabled Mr. Ransome to produce portable 

 filters, by the aid of which the soldier may frequently be enabled to 

 partake of water, which otherwise would be unfit for use. A still 



