Benjamnin F. Butler, Butler's Book: Autobiography and Personal Reminiscences of Major-General Benjamin Butler

[801] would have been no doubt of its success. If it had been only partially successful, it would have had this effect, namely, that no garrison could be kept in a fort where a small naval vessel in the darkness of the night could be run up under it and explode. It would be less expensive to operate on forts in this way than with expeditions for bombardments which might cost millions.

I knew of and acknowledge one great difficulty which those who actually took charge of the preparation of the powder-boat did not seem to appreciate as I did,--that it is very difficult to explode a large mass of army or navy cannon powder without a considerable delay. But if time enough can be had in which the powder may become fully ignited, then it has rapid but not instantaneous explosive force.

Now, I suppose it is not known to many that the cannon powder in the large guns of the army and navy is in the form of square blocks, each from three-quarters of an inch to an inch every way; and that, before any explosive force can be had from it, there must be time given for the blocks to burn. The powder supply for the powder-boat was of that character, and some that was used was admitted to have been damaged powder. But that was all well enough if it had been given time enough to burn. The problem was so to arrange matters that first every portion of the powder in mass should be set fire to at the same instant, and, secondly, after the vessel was run ashore time should be given before the match was applied to the powder to allow the crew having the vessel in charge to get off in their boats.

At a meeting of naval experts at Fortress Monroe at which I was present it was arranged to use a line of fuse known as the Gomez fuse, of which we had samples. This particular kind of fuse is nothing more than an India rubber tube or case of any required shape filled inside with fulminating powder, like in its properties to that used in percussion caps, which burns with great quickness and force, and after once being ignited cannot be extinguished until the mass has been burned out. So quickly does the fire travel through the tube or case that it will go a mile in four seconds. The experiment was tried, a small Gomez fuse one hundred feet long being coiled up in a tub of water, and its two ends brought over the side. An accurate stop watch could not indicate any lapse of time between