the German U-boats.

Captain Reginald R. Belknap, U.S.N., commanding Mine Squadron I of the
Atlantic Fleet, which operated in European waters, has compiled an
interesting account of the important part played by the United States
mine-laying squadron in planting mines in the North Sea. From the time
the United States joined in the war, he says, our Navy Department urged
strong measures, essentially offensive, to hem in the enemy bases, so
that fewer submarines might get out, or, if already out, get back. A new
American invention came to the notice of the Bureau of Ordnance, where
its possibilities were quickly perceived. A few quiet but searching
experiments developed it into a mine of more promising effectiveness
than any ever used before, especially against submarines. This gave the
United States Navy the definite means to offer an anti-submarine
barrage, on the German coast or elsewhere, and the result was the
northern mine-barrage in the North Sea, stretching from the Orkneys 280
miles to Norway, which the Secretary of the Navy's annual report
characterizes as "the outstanding anti-submarine offensive product of of
the year."

Manufacture of the mines in this country--they were of the non-sweepable
variety--had been going on since December, 1917. The many parts were
constructed by the thousands by numerous different contractors, who
delivered them at Norfolk, where the mine spheres were charged with 300
pounds of TNT, and loaded into steamers, managed by the Naval Overseas
Transport Service. It required twenty-four steamers, running constantly,
to keep the ten mine-planters supplied with mines. Only one fell a
victim to a submarine.

Our mine squadron arrived at Inverness May 26, 1918, and twelve days