![]() ![]() ![]() Use of the marine sandglass has been recorded since the 14th century. ![]() There are no records of the hourglass existing in Europe prior to the Late Middle Ages the first documented example dates from the 14th century, a depiction in the 1338 fresco Allegory of Good Government by Ambrogio Lorenzetti. Middle Ages Temperance bearing an hourglass detail Lorenzetti's Allegory of Good Government, 1338 Its predecessor the clepsydra, or water clock, is known to have existed in Babylon and Egypt as early as the 16th century BCE. 350, representing the wedding of Peleus and Thetis (observe the magnification with the object held by Morpheus in his hands) The form of a winged hourglass has been used as a literal depiction of the Latin phrase tempus fugit ("time flies"). The specific duration of time a given hourglass measures is determined by factors including the quantity and coarseness of the particulate matter, the bulb size, and the neck width.ĭepictions of an hourglass as a symbol of the passage of time are found in art, especially on tombstones or other monuments, from antiquity to the present day. Typically, the upper and lower bulbs are symmetric so that the hourglass will measure the same duration regardless of orientation. It comprises two glass bulbs connected vertically by a narrow neck that allows a regulated flow of a substance (historically sand) from the upper bulb to the lower one by gravity. German half-hour sand glass, first quarter of the 16th century, bronze-gilt and silver-gilt, height: 8.3 cm, diameter: 8.4 cm, Metropolitan Museum of Art (New York City) A winged hourglass as a literal depiction of the Latin phrase tempus fugit ("time flies")Īn hourglass (or sandglass, sand timer, or sand clock) is a device used to measure the passage of time. ![]() 298.For other uses, see Hourglass (disambiguation). The invention of clocks and watches largely superseded the practical need for hourglasses. Ships would use the glasses to measure time at sea on a given navigational course. From around 1760, the glass was blown in one piece (with the sand inserted in the cooled end before sealing it). From about 1720, the two bulbs were welded together over a brass bead drilled with a hole, often still bound in leather. In earlier examples the bulbs were connected with a material such as putty or a hardened wax, bound in leather, linen or string. The invention of the hourglass is attributed to an 8th-century monk in Chartres, France, with the marine sandglass appearing as early as the 14th century. There are many other variations of time calibrations for extant hourglasses. Small hourglasses were frequently used in the 20th century to time hard boiled eggs (three minutes) or as game timers. Some marine sandglasses lasted as much as four hours, or came in sets of different durations mounted in a single frame. Often antique hourglasses are timed for an hour (a “true” hourglass) or a half-hour. The sand is usually white and the glass clear, but colored sands or glass were frequently used. Hour glasses were made in a large variety of sizes - typically from an inch or two, up to about 30 inches high. Some revolving stands incorporate a bell: when the sand runs out of the top, the glass inverts itself due to the shift in weight, ringing the bell. Some stands allow for the hourglass to be hung, while others allow the glass to be revolved within the stand. Stands are made from a variety of materials including turned wood metals such as brass, pewter, silver or copper and marble or alabaster. The supports also protect the hourglass against breakage. The hourglass is generally set within a stand with disc shaped ends between three or four supports. ![]()
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