68 



NA TURE 



{May 17, 1883 



Various mechanical devices for effecting the explosion of tor- 

 pedoes by their collision with a ship were employed by the 

 Americans, a few of which proved very effective. Hut although 

 in point of simplicity and cost, a system of defence by means of 

 mechanical torpedoes possessed decided advantages over any 

 extensive arrangements for exploding submarine mines by electric 

 agency, their employment was attended by such considerable risk 

 of accident to those at whose hands they received application 

 that, under many circumstances which were likely to occur, 

 they became almost as great a source of danger to friend as to foe. 



The in >st important advantages secured by the application of 

 electricity as an exploding-agent of submarine mines were as 

 follows : — They might be placed in position with absolute safety 

 to the operators, and rendered active or passive at any moment 

 from the shore ; the waters which they were employed to defend 

 were therefore never closed to friendly vessels until immediately 

 before the approach of an enemy ; they could be fixed at any 

 depth beneath the surface (while mechanical torpedoes must be 

 situated directly or nearly in the path of a passing ship), and 

 they might be removed with as much safety as attended their 

 application. 



There were two distinct systems of applying electricity to the 

 explosion of submarine mines. The most simple was that in 

 which the explosion was made dependent upon the completion 

 of the electric circuit by operators stationed at one or more posts 

 of observation on shore ; such a system depended, however, for 

 efficiency, on the experience, harmonious action, and constant 

 vigilance of the operators at the exploding- and observing- 

 stati >ns, and was, moreover, entirely useless at night, and in any 

 but clear weather. 



The other, which might also be used in conjunction with the 

 foregoing, was that of self-acting mines, exploded either by col- 

 lision with the ship, whereby circuit was completed through the 

 inclosed fuze, or by the vessel striking a circuit closer, where- 

 upon either the mine, moored at some depth beneath, was at 

 once fired, or the necessary signal was given to the operator on 

 sh ire. 



Continental nations bad followed in our footsteps, ; n p ro . 

 viding themselves with equipments for defensive purposes by 

 submarine mines, and the Danes, Swedes, and Norwegians had 

 pursued the subject of submarine mines with special activity and 

 success. 



In the United States the subject of the utilisation of electricity 

 as an exploding-agent for war purposes was being actively 

 pursued, and important improvements in exploding instruments, 

 electric fuzes, and other appliances had been made by Smith, 

 Farmer, Hill, Striedinger, and others already mentioned, while 

 n ) individual had contributed more importantly to the develop- 

 ment of the service of submarine explosions than General Abbot, 

 of the United States Engineers. 



Illustrations of actual results capable of being produced in 

 warfare by submarine operations had hitherto been very few ; 

 but of the moral effects of submarine mines there had already 

 been abundant illustrations. In the war carried on for six years 

 by the Empire of Brazil and the Republic of Uruguay and the 

 Argentine Republic of Paraguay, the latter managed, by means 

 of submarine mines, to keep at bay, for the whole period, the 

 Brazilian fleet of fifteen ironclads and sixty other men-of-war. 

 In the Russo-Turkish war, submarine mines and torpedoes 

 were a source of continued apprehension ; and the French naval 

 superiority was paralysed, during the Franco-German war, by 

 the existence, or reputed existence, of mines in the Elbe. 



The application of electricity to the explosion of military 

 mines, and to the demolition of works and buildings, had been 

 of great importance in recent wars in expediting and facilitating 

 the work of the military engineer. The rapidity with which 

 guns, carriages, &c, were disabled and destroyed by a small 

 party of men who landed after the silencing of the forts at 

 Alexandria, illustrated the advantages of electrical exploding 

 arrangements, combined with the great facility afforded for 

 rapid operations by the power possessed of developing the most 

 violent action of gun-cotton, dynamite, &c, through the agency 

 of a detonator. 



The application of electricity to the explosion of mines for 

 land-defences during active war was not an easy operation, 

 inasmuch as not only the preparation of the mines but also the 

 concealment of electric cables and all appliances from the enemy 

 entailed great difficulties, unless the necessary arrangements 

 could have been made in ample time to prevent a knowledge of 

 them reaching the enemy. 



But few words were needed to recall to the minds of civil 

 engineers the facilities which the employment of electricity to 

 explosive purposes afforded for expediting the carrying out of 

 many kinds of works in which they were immediately interested. 

 Electrical blasting, especially in combination with rock-boring 

 machines, had revolutioni-ed the operation of tunnelling and 

 driving of galleries ; and although in ordinary mining and 

 quarrying operations the additional cost invoh'ed in the employ- 

 ment of fuzes, conductors, and the exploding-machine was not 

 unfrequently a serious consideration, there were, even in those 

 directions, many occasions when the power of firing a number 

 of shots simultaneously was of great importance. There was 

 little doubt, moreover, that accidents in mining and quarrying 

 would be considerably reduced in number if electrical blasting 

 were more frequently employed. 



The conveniences presented by electric firing arrangements 

 under special circumstances were interestingly illustrated by a 

 novel proceeding at the launch of a large screw steamer at 

 Kinghorn in Scotland, which was recently accomplished by 

 placing small charges of dynamite in the wedge-blocks along 

 the sides of the keel and exploding them in pairs, hydraulic 

 power being applied at the moment that the last wedge was shot 

 away. 



In the deepening of harbours and rivers and in the removal 

 of natural or artificial submerged obstructions, the advantages of 

 electric firing were so obvious that extended reference to them 

 was unnecessary. 



A substitute for electrical firing which had been applied with 

 success to the practically simultaneous firing of several charges 

 consisted of a simple modification of the Bickford fuze, which, 

 instead of burning slowly, flashed rapidly into flame throughout 

 its length, and hence had received the name of instantaneous 

 fuze or lightning fuze. The fuze burned at the rate of about 

 100 feet per second ; it had the general appearance of the 

 ordinary mining fuze, but was distinguished from the latter by 

 a coloured external coating. Numerous lengths of this fuze 

 were readily coupled up together so as to form branches leading 

 to different shot-holes, which might be ignited together so as 

 to fire the holes almo-t simultaneously. In the navy this 

 fuze was used as a means of firing small gun-cotton charges 

 to be thrown by hand into boats when these engaged each 

 other, the fuze being fired from the attacking boat by means 

 of a small pistol, into the barrel of which the extremity was 

 inserted. 



THE IRON AND STEEL INSTITUTE 



■"THE annual meeting of this society took place at the Institution 

 of Civil Engineers on May 9, 10, and 11 last. On the 

 first day the chair was taken by the retiring president, Mr. Josiah 

 T. Smith, but after some formal bu-iness had been goue through 

 he vacated it in favour of the president elect, Mr. B. Samuelson, 

 M.M., F.R.S. The latter proceeded to read an able address, 

 dealing mainly with the great progress which had taken place in 

 the iron and steel industries since the Institute was founded in 

 1S69. He remarked on the very large makes of pig iron which 

 were now going on in American blast furnaces, and stated that 

 these were found to be economical even as regards fuel and wear 

 and tear of the lining. He then dwelt at some length on im- 

 provements in the manufacture of coke, especially with a view 

 to recovery of the waste products. The deterioration which was 

 feared would result as regards the coke itself had not appeared in 

 the case of the Simon-Carves ovens, worked by Messrs. Pease 

 and Co., who were recovering oil and tar to the value of 4^. 2d. 

 per ton of coal. Against this was to be set increased expenses 

 to the amount of Is. 41/. per ton of coke, and also interest on first 

 co-t and maintenance. He further referred to the Jameson pro- 

 cess lately described before the Ii stitution of Mechanical Engi- 

 neers, and observed that this principle was being applied to 

 recover oil and ammonia from smouldering waste-heaps at the 

 pit bank. Passing on to the manufacture of steel he spoke with 

 much approval of the Bicheroux gas puddling furnaces at Ougree 

 in Belgium, where gas obtained from slack was used for puddling, 

 and gave more heat for steam-raising purposes than the old 

 system. Speaking of the future demand for iron and steel, he 

 pointed out that the United States had fifty times and Russia five 

 times as many miles of railway per million of people as had our 

 Indian Empire ; and strongly urged the further development of 

 railways in the latter country. The address also touched upon 

 many other points connected with iron and steel, such as the 



