Amplitude

[From Lat. amplus, large.] The state of being ample; extent; largene . (Astron.) The angular distance of a celestial body from the east point when it rises, or from the west point when it sets. It depends upon the declination of the star and the latitude of the place. It must be measured toward the N. and S. points of the horizon, according as the declination is N. or S. For the fixed stars, the A. remains the same throughout the year; but for the sun it varies with the declination. (Gun.) A. is sometimes used for the range of a shell. or other projectile, from its departure out of the mouth of the piece to the place where it falls. Thus, French engineers speak of the A. de parabole , . Magnetical amplitude , with reference to the direction of the magnetic needle or compa , the arc of the horizon contained between the sun or a star, as its rising or setting, and the magnetical E. or W. points of the horizon; or it is the difference of the rising or setting of the sun or star from the E. or W. points of the compa . Am'pul, n. See AMPULLA. Ampulla, n. [Lat., a bottle.] A ve el bellying out like a jug, used by the ancient Romans, either for containing unctions for the bath, or for drinking at table. (Eccl. Hist .) A ve el for holding the oil at Chrismation, consecration, .; also for anointing monarchs at coronation. In France and England, a ve el of this kind was in use for the last-mentioned purpose. The French A. was at Rheims, the archbishop of which city performed the act of coronation of the French kings. A dove, it is said, brought this A. from heaven for the baptismal unction of Clovis I., in 496. In the revolution, this A. was lost; and it is said that a soldier oiled his boots with the miraculous liquid. On the coronation of Charles X., the last monarch anointed, it was stated that a phial containing some of this unction had survived the catastrophe. The A. of the English kings was in the form of an eagle, weighing about 10 ounces, of the purest chased gold. It was deposited by the Black Prince in the Tower of London. Henry IV. is the first king who was anointed from it. (Chem.) A big-bellied ve el. ( Bot .) A bladder-shaped bag. Ampulla/ceo us, a. Having the form of a bottle or inflated bladder. Ampullar i a, n . [Lat. ampulla , a globular flask.] ( Zool .) A gen. of Mollusca, of the fam. Ampullariida.q . v. Ampullar i'idæ, n. pl. (Zoöl. A family of fresh-water gasteropodous Mollusca , the shell of which is large, thin, and globular. In addition to their gills they are said to have a bag which opens beneath, placed on the side of the respiratory cavity, which they can prob ably fill with water. It is most likely by means of this apparatus that the animals have the power of surviving a long drought or removal from the water, individuals having been known to live after having been packed up dry for a year or two.