upon it another duty of great responsibility. The submarines had to be
ever ready to go south at a moment's notice to cover the eastern
approach to the English Channel against the enemy capital ships,
should these attempt to break through. Had the Germans made the
attempt in earnest, there is no doubt that they would have had to pay
a very heavy toll.

Admiral Sir David Beatty put it well when, in a speech delivered in
Edinburgh, he spoke of our "submarine sentinels who carried out the
same services as the storm-tossed frigates of Cornwallis off Brest."

The only British submarines that were adapted for the laying of mines
were those of the Harwich Flotilla. Consequently, for a considerable
time plenty of arduous, perilous work among the minefields fell to
their lot.

The mine-laying submarines of the Harwich Flotilla were especially
busy on the eastern side of the North Sea, where our great minefields
were. Captains of submarines describe this portion of the sea as an
ideal one for submarine work; for the depth of the water is generally
of from twenty to thirty fathoms, at which depth a submarine can lie
comfortably at the bottom without being subjected to an excessive
pressure. Comfortable is, of course, a relative term. Most people
would never be anything but extremely uncomfortable in the atmosphere
of a submarine after she has been submerged for some hours. A
fresh-air crank would die in it.

The great minefield which was declared by our Government in the summer
of 1917, the preparation of which was a gigantic undertaking, extended
from the Frisian Islands to about latitude 56 degrees north. The
Dutch, for their own purposes, removed their lightships from their
coasts to the western side of this minefield, thus forming a line of
lights running north and south, roughly along the 4th degree of east
longitude. This our sailors facetiously named Piccadilly Circus. It
was the business of the submarines to lay mines on the eastern part of
this minefield, that is, near to the coast. Our surface mine-layers
laid their mines further seaward; while still further west our large
mine-laying ships, one of which can carry as many as three hundred
mines, laid their mines just inside Piccadilly Circus. Our submarines
used to patrol regularly along Piccadilly Circus to look out for and
attack enemy ships, and at intervals went shorewards through the
minefield in order to reconnoitre.

A mine-laying submarine used to adopt the