Following the conference on board the _Queen Elizabeth_, our bases worked full blast on the mines for the first operation. One group assembled and tested the anchors, another the mines, a third the plummet, a fourth the plummet and anchor together, and a fifth, the final assembly, of mine and anchor complete—called a unit. A section of mine track of standard gauge sufficed to test the anchor wheels and thus obviate trouble on board from their binding or dropping between the ship’s tracks during minelaying, possibly causing an interrupted string. It speaks well for the manufacture, for the testing at the bases, and for the ship’s mine track installations, that no such interruption ever occurred in the whole series of operations. [Illustration: MINES AND MINE ANCHORS AWAITING ASSEMBLY. The Anchors were Shipped in Pairs, for Convenience in Handling.] The adjustment of firing mechanism was done in a locked room, the secret entrusted only to a few. It was delicate work, to be done patiently and methodically, for its accuracy determined whether the mine would be alive—or a dud. Fidelity in such adjustments is hard enough to maintain when the repetitions are numbered only by tens. Where hundreds and thousands are involved the tax on attention becomes severe. Before loading the mines into the cars, for transfer to the lighters, each mine was primed with a mealed TNT “booster” charge and the firing detonator was put in place—all ready for the laying—and five safety devices were seen in place and in order. These devices would prevent the firing mechanism working until the mine had reached a certain minimum depth under water and had been in the water about 20 minutes, and would also prevent exploding in case of loss overboard during embarking. Such devices usually function properly, and dependence is not placed on one alone but on several together, any one of which will make the mine safe to handle—by experienced men. At an early stage in the training in mines, one learns to treat them with respect always—no liberties. Even the safest explosives, the surest mechanism, have an occasional, inexplicable aberration. [Illustration: LOADING MINES INTO LIGHTERS. At Base 18, on the Caledonian Canal, at Inverness.] The ready mines are swung up into open freight cars, for hauling to the water side, whence they go, 40 to 80 together, in lighters out to the ships. After being landed on the tracks of the minelayer, one safety pin is removed—leaving four—and the mine is then examined for any derangement during the three handlings in transit from the store shed.