Illustrated Companion to the Latin Dictionary/Hydraulus

This article incorporates text from a publication now in the public domain: Rich, Anthony (1849). The illustrated companion to the Latin dictionary, and Greek lexicon. p. vi. OCLC 894670115. https://archive.org/details/illustratedcompa00rich. 

HYDRAU'LUS (ὕδραυλος or -ις). A water organ (Cic. Tusc. iii. 18. Plin. H. N. ix. 8. Vitruv. x. 13.); in which the action of water was made to produce the same effect upon the bellows as is now procured by a heavy weight. The instrument is rudely indicated by the annexed engraving (Hydraulus/1.1), from a contorniate coin of the Emperor Nero; and in the collection of antiquities bequeathed to the Vatican by Christina of Sweden, there is a medal of Valentinian, which has a representation of a similar instrument on the reverse, accompanied by two figures, one on each side, who seem to pump the water which works it. It has only eight pipes, is placed upon a round pedestal, and, like the present example, affords no indication of keys, nor of any person performing upon it; whence it has been inferred that these organs were only played by mechanism.

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  Hydraulus/1.1