We began this work with practically nothing; we had to obtain ships and transform them into mine-layers; to enlist and to train their crews; to manufacture at least 100,000 mines; to create bases both in the United States and Scotland; to transport all of our supplies more than 3,000 miles of wintry sea, part of the course lying in the submarine zone; and we had to do all this before the real business of planting could begin. The fact that the Navy made contracts for 100,000 of these new mines before it had had the opportunity of thoroughly testing the design under service conditions shows the great faith of the Navy Department in this new invention. More than 500 contractors and sub-contractors, located in places as far west as the Mississippi River, undertook the work of filling this huge order. Wire-rope mills, steel factories, foundries, machine shops, electrical works, and even candy makers, engaged in this great operation; all had their troubles with labour unions, with the railroads, and with the weather—that was the terrible winter of 1917-18; but in a few months trainloads of mine cases—great globes of steel—and other essential parts began to arrive at Norfolk, Virginia. This port was the place where the mine parts were loaded on ships and sent abroad. The plant which was ultimately constructed at this point was able to handle 1,000 mines a day ; the industry was not a popular one in the neighbourhood, particularly after the Halifax explosion had proved the destructive powers of the materials in which it dealt. In a few months this establishment had handled 25,000,000 pounds of TNT. The explosive was melted in steel kettles until it reached about the density of hasty pudding ; with the aid of automatic devices it was then poured into the mine cases, 300 pounds to a case, and thence moved on a mechanical conveyor to the end of the pier. Twenty-four cargo vessels, for the most part taken from the Great Lakes, carried these cargoes to the western coast of Scotland. Beginning in February, 1918, two or three of these ships sailed every eight days from Norfolk, armed against submarines and manned by naval crews. The fact that these vessels were slow made them an easy prey for the under-water enemy; one indeed was sunk, with the loss of forty-one men; regrettable as was this mishap, it represented the only serious loss of the whole expedition.
