Hyalotype (ὕαλος, glass, and τυπεῖν, to print). An invention for printing photographs from the negative on to glass, instead of paper.
Hycsos, Egyp. (lit. impure). A people of unknown origin, nomad tribes, but not savages, as has hitherto been believed, who came from Sinai, Arabia, and Syria. They are known as Poimenes (the Shepherds), Mentiou Sati, Asian Shepherds, and even Scourges, from their invasion of some part of Eastern Egypt.
Fig. 390. Hydra with seven heads.
Hydra, Gr. (a water-serpent). A hundred-headed monster of Greek mythology, sprung, like the Chimæra, from Typhon and Echidna; he was killed by Hercules. In Heraldry the hydra is represented with only nine heads. The illustration (Fig. [390]) is of the device adopted by Curtio Gonzaga, an Italian poet, to symbolize the constancy of his love, with the motto, “If I kill it, more strong it revives.”
Hydraletês, Gr. (1) A mill for grinding corn, driven by water. (2) A waterfall or current of water.
Hydraulis, Gr. (ὕδρ-αυλις). A water-organ. The hydraulic organ, invented about B.C. 200, was really a pneumatic organ; the water was only used to force the air through the pipes. It is represented on a coin of Nero in the British Museum. Only ten pipes are given to it, and there is no indication of any key-board. It had eight stops, and consequently eight rows of pipes; these were partly of bronze, and partly of reed. It continued in use so late as the 9th century of our era.
Fig. 391. Hydria, or Water-jug, in black glaze.
Hydria, Gr. A large, heavy vessel, used principally for holding a store of water. It is represented urn-shaped, with a broad base and a narrow mouth, sometimes with one and sometimes with two handles at the top, and smaller ones on the belly. The name is applied to other pails of bronze or silver, &c. (Fig. [391].)