Achelor, Achlere or Ashlar. (Arch.) Hewn stone.
Achromatic, Gr. (α priv. χρομος, colour). The effect of an arrangement of lenses by which a coloured ray of light is rendered colourless.
Acicula, Gr. (dimin. of acus, a needle or pin). In particular a bodkin used by the Roman ladies to keep the hair in its place when curled or plaited, and to keep on false hair. The words acicula and acus are however all but synonymous. The former does not denote a bodkin of smaller size than the acus, but an object made of an inferior material; the acus being of silver, ivory or gold, while the acicula was simply of bone or some hard wood such as box, myrtle, olive, &c.
Fig. 6. Acinaces.
Acinaces, Orient. (ἀκινάκης; orig. a Persian word). A straight poniard resembling a very short Roman sword, used by the Eastern nations of antiquity, especially, the Medes, Persians and Scythians. It was worn by soldiers suspended from a belt round the waist, but the weapon hung either at the right or the left side, according to the nationality and accoutrements of the soldier. When, however, he wore a sword, this was always placed at the left, and the acinaces at the right side of the body. The handles of these weapons are generally extremely rich.
Acisculus, R. (Diminutive of ascia, an adze = a small adze). A small pick employed by stone-cutters and masons in early times. Representations of it may be seen pretty frequently on medals, in especial those of the Valerian family. [See Ascia.]
Acketon, Fr. A quilted leathern jacket, worn under the armour, introduced from the East by the Crusaders.
Aclis or Aclyx, R. A sort of harpoon, consisting of a thick short stock set with spikes. This massive weapon was chiefly employed by foreign nations, but not by the Romans. It was launched against the enemy, and drawn back by means of a cord to which it was attached, to be launched a second time. This weapon bears some resemblance to a particular kind of angon (or trident). (See Angones.)
Acoustic Vases, R. (Gr. ἀκουστικὸς, pertaining to the sense of hearing). Vases of earthenware or more often of bronze, which, in the theatres of antiquity, served the purpose of strengthening the voices of the actors. Vases of this kind would also seem to have been employed for the same purpose during the middle ages, for the architect Oberlin, when repairing the vault of the choir, in the ancient church of the Dominicans at Strasburg, discovered some acoustic vases there.