• Webster's Revised Unabridged Dictionary
    • n Sympiesometer A sensitive kind of barometer, in which the pressure of the atmosphere, acting upon a liquid, as oil, in the lower portion of the instrument, compresses an elastic gas in the upper part.☞ The column of oil of a lower part BC of a glass tube compresses hydrogen gas in the upper part AB, and is thus measured on the scale pq by the position of a surface of the oil in the tube. The scale pq is adjustable, and its index must be set to the division on the scale rs corresponding to the temperature indicated by the termometer t, in order to correct for the effects of temperature on the gas. It is sensitive, and convenient for use at sea, but inferior in accuracy to the mercurial barometer.
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Century Dictionary and Cyclopedia
    • n sympiesometer An instrument for measuring the pressure of a current. Two tubes are so bent that their upper parts rise vertically above the water. The submerged parts are bent one up the other down stream, and are open at these ends. The vertical parts are joined to one tube from which the air is partially sxhausted,so that the level of the water in both tubes can be seen. The difference of levels shows the force of the current.
    • n sympiesometer A form of barometer in which the pressure of the atmosphere is balanced partly by the weight of a column of liquid and partly by the elastic pressure of a confined mass of gas. As originally constructed by Adie of Edinburgh, it consists of a short inverted siphon-tube, with a bulb blown on the end of the longer leg, while the shorter leg is left open. The bulb and the upper end of the tube are filled with air or hydrogen, and the lower part of the tube with glycerin. The pressure of the atmosphere exerted upon the surface of the liquid is balanced by the pressure of the inclosed gas and by the weight of the column of liquid which is supported. The level of the liquid constitutes the reading of the instrument. At each observation the scale is adjusted for the temperature, and an attached thermometer forms an essential auxiliary. The sympiesometer is more sensitive than the mercurial barometer, but it does not so well maintain its constancy, and its readings cannot be so accurately corrected and evaluated. An improved form of the instrument consists essentially of a cistern-barometer, with air above the column of liquid instead of a vacuum. The measurement consists in determining the height of a column of liquid required to keep the inclosed air compressed into a standard volume. By this method of use the theory of the instrument is simplified, and the readings are easily evaluated. Also sympiezometer.
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Chambers's Twentieth Century Dictionary
    • n Sympiesometer sim-pi-e-som′e-tėr a barometer in which oil and hydrogen gas replace mercury and the Toricellian vacuum: an instrument for measuring the pressure of a current.
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Webster's Revised Unabridged Dictionary
Gr. compression (fr. to press together; sy`n with + to press, squeeze) + -meter,
Chambers's Twentieth Century Dictionary
Gr. sympiesis, a pressing together—syn, with, piezein, to press, metron, a measure.


In literature:

The height, as measured by a sympiesometer, was about 2,800 feet.
"The Malay Archipelago" by Alfred Russell Wallace
They, as well as sympiesometers, are likewise dependent or secondary instruments, and liable to deterioration.
"Barometer and Weather Guide" by Robert Fitzroy
Small pocket sympiesometers are sometimes fitted with ivory scales, and protected by a neat velvet-lined pasteboard or morocco case.
"A Treatise on Meteorological Instruments" by Henry Negretti
The sympiesometer had been more on the alert, and had fallen more rapidly.
"Narrative of the surveying voyages of His Majesty's ships Adventure and Beagle, between the years 1826 and 1836" by Robert FitzRoy