and firing mechanism in a separate bl10y called a " contact buoy ...

400 TEXT BOOK OF ORDNANCE AND GUNNERY
up oars. Take all the boats in tow of a steamer, the lengths of
the tow lines or painters being equal to the distances at which the
mines are to be spaced when anchored. The tow then proceeds,
as before, to the point where the mines are to be laid and steers
along the line, the crew of each boat being ready to slip its mine.
Wheri in position the towing boat makes a signal and all the mines
are slipped simultaneously and all tow lines are cast off. If the
mines are dropped promptly, it will not be necessary for the boats
to anchor. In case of a hitch, however, a boat may anchor in position
until its mine is dropped. All boats then get up oars and
pull on parallel courses at 4 or 8 points from the line of mines and
drop their respective batteries and safety breaks as before. The
steamer may then take the boats in tow again and return to the
ship, if necessary, for another lot of mines.
In this manner each ship of a squadron may quickly lay a line of
mines in accordance with a plan previously decided upon, and
each ship's force, knowing exactly how and where its mines were
planted, may pick them up without delay. The sketch illustrates
this method, the boats, mines, batteries and safety breaks being
numbered as before.
33. The Future of Blockade Mines.-If the claims of inventors
are even approximately realized, submarine mines may play an
important part in future naval wars. A squadron, or a single
ship, may protect itself from attack by quickly mining the approaches
to a harbor in which it takes refuge; or an inferior naval
force may successfully blockade an enemy in port by laying lines
of mines across the entrance, and then protecting the mine field
from countermining operations. With such a system of blockade
mines, Cervera's squadron might have been effectively blockaded