Operations as a whole were conducted in conjunction with a British mine-laying squadron of four vessels, under command of Rear Admiral Clinton-Baker. American and British squadrons often went out at the same time, under protection of the same heavy vessels, but except on two occasions they worked separately, in different parts of the barrage area. Thus there were altogether fourteen mine planters at work at the same time. On the first excursion, June 7th, the American squadron planted a mine field 47 miles long, containing 3,400 mines, in 3 hours and 36 minutes. Everything went without a hitch. One ship emptied herself of 675 mines without a single break, one mine every 11-1/2 seconds through more than two hours, a record never before equalled. [Illustration: ONE OF THE PERILS OF MINE-SWEEPING An explosion close astern of the Patapsco. The greatest care was exercised to avoid accidents of this character, but to eliminate them entirely was impossible.] [Illustration: THE MINE-SWEEPERS PROVED WONDERFUL SEA BOATS These tiny craft rode many a rough sea which worried larger and more powerful ships.] [Illustration: UNITED STATES NAVAL OFFICES IN IMPORTANT COMMANDS Left to right: Admiral Sims, Admiral Mayo, Captain Nathan C. Twining, Captain O. P. Jackson, Admiral Wilson.] [Illustration: AMERICAN AND BRITISH NAVAL OFFICIALS Left to right: Admiral Benson, Secretary Daniels, Sir Eric Geddes, Admiral Duff.] Dangerous as was the work, there were very few casualties. One man fell overboard from the _Saranac_ and was drowned, but he was the only man lost at sea, and there were but four other deaths in that force of 4,000. Laden with high explosives, navigating waters where enemy mines had been laid, operating near mine fields, and in danger of premature explosion from those they themselves had laid, it is remarkable that not one of these ships was lost or seriously damaged. The eighth excursion in which British and American squadrons joined, both in command of Admiral Strauss, closed the western end of the barrier, off the Orkneys. The next expedition was conducted in the same manner, with Rear Admiral Clinton-Baker, of the British Navy, in command. The American squadron made fifteen excursions, the British eleven, operations being completed October 26th. In four hours on one expedition, 6,820 mines were planted, 5,520 by our vessels, 1,300 by the British. Our squadron alone planted a field 73 miles long in one day. Seventy thousand, two hundred and sixty-three mines were laid--13,652 British, 56,611 American. Numerous lines were laid near the surface; others were placed at from 90 to 160 feet; and the lowest went to depths from 160 to 240 feet.