ICE-PLANK. See [Spike-plank].

ICE-QUAKE. The rending crash which accompanies the breaking of floes of ice.

ICE-SAW. A huge saw for cutting through ice; it is made of 2⁄8 to 3⁄8 inch plates of iron, and varies in length from 10 to 24 feet.

ICE-SLUDGE. Small comminuted ice, or bay-ice broken up by the wind.

ICE-TONGUE. See [Tongue].

ICHNOGRAPHY. A ground plot or plan of a fortification, showing the details of the construction as if cut horizontally through.

ICK. An Erse or Manx term for a creek or gullet.

IDLER. A general designation for all those on board a ship-of-war, who, from being liable to constant day duty, are not subjected to keep the night-watch, but must go on deck if all hands are called during the night. Surgeons, marine-officers, paymasters, and the civil department, are also thus denominated.

IDOLEERS. The name by which the Dutch authorities are known in their oriental colonies, the designation being a corruption of edle herren.

IGNORANCE. If a loss happen through the ignorance of the master of a ship, it is not considered as a peril of the sea; consequently the assurers are not liable. Nor is his ignorance of admiralty-law admissible as an excuse.