Labor was scarce in the Highlands and the weather that winter was severe. The work went slowly, delayed considerably beyond expectation. Captain Murfin had many discouragements, and disappointments in deliveries from the United States. In spite of the kindness of all about him, he must often have felt very far away from home; but afterwards, the frank admiration repeatedly expressed by all visitors to the bases must have repaid his six long months of effort. In the end, the bases were ready in time, and their capacity, and the rate of transportation as well, were twice the original estimate, the two bases together being capable of assembling 1000 mines a day ready for planting. Sending over the base personnel began with small drafts in December, but as accommodations for the full number were not ready soon enough, and the demand to use all transportation for troops became pressing during the Germans’ great drive in March, 1918, the base complements were not more than about two-thirds full when the mine squadron sailed from the United States coast in May. The greater part, 750, of the number then lacking had therefore to be brought over by the squadron. Though this retarded the proper organizing of the base personnel, it did not delay the minelaying. CHAPTER FOUR THE SUPPLY OF MINES In the same past six months other preparations, too, had been pushing ahead, both at home and abroad. Providing the mines—the task of our Naval Bureau of Ordnance—would alone make a story of great interest. Considering how long it had taken to develop previous types of mines, to have made a success of an invention that was new since our entering the war was indeed remarkable, the more so from inability to test a single mine complete before ordering 100,000. [Illustration: A MINE IN MID-AIR, BEING HOISTED IN. The Plummet is at the Lower Left Corner.] Mines for the open sea in great numbers, moored “flying”—that is, by ships steaming at considerable speed—need anchors with automatic depth regulation. Such mechanism had undergone important changes during the war, and the new American mines needed all the improvements, to make them sure to plant at the intended level. They were to be much deeper than ever attempted before, and also in deeper water. [Illustration: LAUNCHING A MINE THROUGH THE STERN PORT. There is a Nine-Foot Drop, from Rails to Water.] Three British officers of considerable mine experience assisted here, Lieut. Commander H. O. Mock, R.N.R., Lieutenant R. H. DeSalis, R.N., and Lieut. Commander Harold Isherwood, R.N.V.R. The last was an expert designer, and had an important part in planning our new mine anchor, which was similar to a late model British mine anchor.