clepsydra


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Related to clepsydra: water clock

clepsydra

(klĕp`sĭdrə) or

water clock,

ancient device for measuring time by means of the flow of water from a container. A simple form of clepsydra was an earthenware vessel with a small opening through which the water dripped; as the water level dropped, it exposed marks on the walls of the vessel that indicated the time that had elapsed since the vessel was full. More elaborate clepsydras were later developed. Some were double vessels, the larger one below containing a float that rose with the water and marked the hours on a scale. A form more closely foreshadowing the clock had a cord fastened to the float so that it turned a wheel, whose movement indicated the time. A further step was the use of gear wheels and a turning pointer. It is believed that clepsydras were used in Egypt c.2000 B.C.; from Egypt they were introduced into Greece and later from there into Rome.
References in periodicals archive ?
(80.) Al-Wabkanawi uses the term pangon in the otherwise similar paragraph in his own Zij, which is originally a simple Iranian clepsydra (Arabicized as bankam) in the shape of a floating bowl (as), having a hole in its apex and two graduated scales (usually drawn with the aid of an astrolabe) for both equal and unequal hours on its peripheral surface.
Image of clepsydra from The Power of Water by Helen Chapman, Reed International Books Australia Pty Ltd (1966), as shown in 2005 BST, reproduced with permission from Pearson Australia Group.
Another early timekeeper used by the Egyptians and Greeks was the clepsydra (KLEP se drah) or water clock.
The Hall of Union displays one of the most marvelous scientific inventions of ancient China--a clepsydra (water clock).
Her Clepsydra, 2000, a bottle suspended mouth down from a stainless-steel brace, drips an indigo solution onto the fl oor, as if to inaugurate a ceremony fusing western antisepsis and African ritual.
The last three essays deal with timepieces, the compartmented cylindrical clepsydra or water clock, devices of considerable mechanical sophistication; the seventeenth-century table clepsydra; and some seventeenth-century efforts towards the construction of magnetic timepieces, many doomed because they relied on perpetual motion, even if they were inspired by a hint from William Gilbert.
Pontefract: 3.20 Paragon of Virtue, 4.25 Clepsydra, 5.30 Lucky Gitano.
Henry Cecil has just one runner this afternoon and CLEPSYDRA (4.45) can make the trip to Yorkshire a fruitful one.
John Ashbery's "Clepsydra" (Rivers and Mountains), a bewildering torrent of a poem, becomes more intelligible on discovery of an internal structure: it is bounded at each pole by the figure of circumference, which appears first at line 40, near the poem's beginning, and again at line 248, at its end.
H Offer loads of product information: Web stores may not create the touch-and-feel immediacy of a well-designed package in a retail store, but the Web can do a far better job of answering key customer questions, says Segiu Simmel of Clepsydra Systems.
The Greeks called the device a clepsydra (water-stealer), since the water quietly leaked out of the upper chamber.
A reader previously unacquainted with Ashberry's central work may trace its development from many of the poems in Some Trees through "A Last World" in his second book, The Tennis Court Oath (1962), through "Clepsydra," "The Skaters" and the title poem of Rivers and Moutains (1966), on through "Soonest Mended" and "Fragment" in the 1970 volume, The Double Dream of Spring.