Piriform, Arch. Pear-shaped. The term is applied to roofs domed in the form of a pear; the Baptistery of Parma may be cited as an example.
Pirogue. An Indian canoe, hollowed out of a solid tree.
Piscina, R. (piscis, a fish). (1) A fishpond, an indispensable appendage to the villa of a wealthy Roman. (2) A large uncovered tank in the open air used as a swimming-bath, and distinct from the baptisterium, which was under cover. (3) Piscina limaria was the reservoir of an aqueduct. In mediæval archæology the name was given (1) to credence-tables; (2) to baptisteries. (See Baptisterium, Natatorium.)
Pisé-work. A method of constructing very durable walls of blocks of kneaded earth. It was probably suggested by the building processes of the ants, and Pliny calls such walls formaciæ.
Pistillum, Pistillus, R. A pestle for a mortar.
Pistol. Invented at Pistoia in Tuscany. (See Pallas Armata, Sir James Turner, 1670; Meyrick, iii. 76.)
Pistole. A Spanish gold coin, worth about 16s.; the fourth of a doubloon.
Pistolese, It. A long dagger or stabbing-knife of Pistoia.
Pistrina, Pistrinum, R. (pistor, a miller). Originally this term denoted a mill for grinding grain; later on it was used exclusively to denote a house of correction for slaves who had to turn the mill. The work was of a most laborious kind.
Pistris, Pistrix, R. (πίστρις). (1) A marine monster, representations of which are to be seen on the walls of several houses at Pompeii (in the legend of Theseus and Andromeda). It is always represented with the head of a dragon, and the fins and tail of a fish; and was adopted in early Christian art for the fish that swallowed Jonah. (2) A military engine.