_Colt's Electric Cable._--The electric cable as used by Colonel Colt, was insulated by cotton yarn, soaked in a solution of asphaltum and beeswax, and the whole enclosed in a metal case.
_Colt's Reflector._--On examining Colt's papers after his death, one was found illustrating one of his many devices for effecting the explosion of a submarine mine at the proper instant.
_Description of Reflector._--One set of conducting wires from all the mines is permanently attached to a single pole of a very powerful firing battery, the other wires lead to metal points which are attached to marks on a chart of the channel in front of the operator and which marks correspond with the actual positions of the mines in the channel. A reflector, is arranged to throw the image of a hostile vessel on the chart, and as this image passes over either of the wire terminations on it, the operator with the other battery wire, completes the circuit, and explodes the torpedo, over which by her image thrown on the chart, the vessel is supposed to be at that precise moment.[F] In his experiment with a vessel under weigh, Colt had probably taken the precaution of laying down several circles of mines, and thus aided by cross staffs, ensured the experiment being a success.
With regard to the invention of the word torpedo, for submarine infernal machines, Dr. Barnard in his life of Colt says, "that Fulton used the word torpedo, probably on account of its power of stunning or making torpid, and that a long way through the water,--in so naming it, he buildeth better than he knew, for Colt's torpedoes being fired by electricity may with special fitness take its name from the electric eel."[G]
_Theoretical Knowledge._--Though many opportunities have occurred during the last thirty-five years for practically testing the effectiveness of torpedoes when employed on actual service, especially during the American Civil War (1861-65) and the late Turco-Russian War (1877-78), yet in so far as the offensive and electrical portion of submarine warfare is concerned, our knowledge of them is still principally theoretically.
_Failure of Offensive Torpedoes._--The manipulation of the ordinary spar or outrigger torpedo boats, and of the various automatic torpedoes, appears simple enough, when practice is made with those submarine weapons during peace time, also the results of such practice is without doubt uniformly successful, yet when the crucial test of actual service is applied, as was the case during the war of 1877, with the Whitehead and spar torpedoes, then a succession of failures had to be recorded.[H]