Observers recorded the number, times, and approximate positions of all explosions and, on board the _San Francisco_ and _Baltimore_, there were listeners stationed at the submarine signal receivers, so as to get a full count. All observers did not agree, as the indications from sounds and shocks varied according to distance and depth. Some explosions gave a prolonged reverberation, at times sounding to the unassisted ear like two or three explosions in rapid succession, but in the submarine signal receiver each explosion made a distinct sound, unmistakable. The count by the _San Francisco_ and _Baltimore_, differing by only 2, practically agreed on 100 explosions, or about 3 per cent of all mines planted. Although a perfect record was desirable, the detonations showed the minefield to be alive and sensitive, and their number was not large for a new mine, not yet long enough in service to refine out the minor defects. Surprising enough on deck, where one could see, that first explosion must have startled the men in the engine room, in the coal bunkers, and on the lower mine decks. The blow rings sharper down there, where resulting damage, in broken pipe joints or started boiler tubes, might be expected first. Whether gun, torpedo, or mine, however, it is all one—the duties go on just the same. As the mines on the launching deck move slowly aft, those on lower decks move forward, to the elevators and up. Working spaces are cramped, passages narrow, bulkhead doors closed wherever possible. At the right time, a door will be opened, the portable section of mine track adjusted, the mines in that compartment hauled out, and the door closed again water-tight, all as quickly as possible. Close, hot, foul with oily steam and seasickness—it is sweating, disagreeable work below decks. But complaint is nowhere in the ships. The feeling is well expressed by one man, writing home: When the first mine went over, I had a curious feeling of exultation. The fear, the perils, the uncertainties that surround our work, slipped from me like the foolish fancies of a nightmare. There, at last, was a nail in the Kaiser’s coffin. Come what might, I had justified my existence. Had the whole German High Seas Fleet appeared in the offing, I am sure I should have gone to my battle station with a shout of glee. Prolonged activity, in preparing the squadron and bringing it out, makes it trying now for me, to look on, hands folded—nothing to do while everything goes well—yet constantly alert, for instant decision in case of mishap. After nearly four hours, the schedule is finished. Some marker buoys are dropped, for later use in beginning another minefield. The line of ships then takes the narrower route formation, and we head back for the base. Butler, Canaga, and I exchange quiet congratulations. Our work together has been to good purpose.