ATLANTIC. The sea which separates Europe and Africa from the Americas, so named from the elevated range called the Atlas Mountains in Morocco.
ATLANTIDES. The daughters of Atlas; a name of the Pleiades.
ATLAS. A large book of maps or charts; so called from the character of that name in ancient mythology, son of Uranus, and represented as bearing the world on his back. Also the Indian satin of commerce.
ATMOSPHERE. The ambient air, or thin elastic fluid which surrounds the globe, and gradually diminishing in gravity rises to an unknown height, yet by gravitation partakes of all its motions.
ATMOSPHERIC or Single-action Steam-engine. A condensing machine, in which the downward stroke of the piston is performed by the pressure of the atmosphere acting against a vacuum.
ATMOSPHERICAL TIDES. The motions generated by the joint influence of the sun and moon; and by the rotatory and orbital course of the earth,—as developed in trade-winds, equinoctial gales, &c.
ATOLLS. An Indian name for those singular coral formations known as lagoon-islands, such as the Maldive cluster, those in the Pacific, and in other parts within the tropics, where the apparently insignificant reef-building zoophytes reside.
ATRIE. To bring the ship to in a gale.
A-TRIP. The anchor is a-trip, or a-weigh, when the purchase has just made it break ground, or raised it clear. Sails are a-trip when they are hoisted from the cap, sheeted home, and ready for trimming. Yards are a-trip when swayed up, ready to have the stops cut for crossing: so an upper-mast is said to be a-trip, when the fid is loosened preparatory to lowering it.
ATTACHED. Belongs to; in military parlance an officer or soldier is attached to any regiment or company with which he is ordered to do duty.