ATHWART. The transverse direction; anything extending or across the line of a ship's course.--_Athwart hawse_, a vessel, boat, or floating lumber accidentally drifted across the stem of a ship, the transverse position of the drift being understood.--_Athwart the fore-foot_, just before the stem; ships fire a shot in this direction to arrest a stranger, and make her bring-to.--_Athwart ships_, in the direction of the beam; from side to side: in opposition to _fore-and-aft_. ATHWART THE TIDE. _See_ ACROSS THE TIDE. 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. ATTACK. A general assault or onset upon an enemy. Also the arrangement for investment or battle. (_See_ FALSE ATTACK.) ATTEMPT, TO. To endeavour to carry a vessel or place by surprise; to venture at some risk, as in trying a new channel, &c. ATTENDANT MASTER. A dockyard official. (_See_ MASTER-ATTENDANT.) ATTENTION. A military word of command, calling the soldier from the quiescent position of "at ease" into readiness for any exercise or evolution. Also the erect posture due to that word of command, and which is assumed by a private soldier in the presence of an officer. The attending to signals.