Evolution of the Thermometer, 1592-1743 Volume 1-1900

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1900 edition. ... was patterned after it), and was the first that could be used for all liquids. In the fifth paper Fahrenheit describes his invention of the thenno-barometer, based on the fact that the boiling-boint of water is influenced by barometric pressure. Boyle had observed the lowering of the boiling-point under the receiver of the air-pump, but Fahrenheit was the first to discover the principles of hypsometry. Fahrenheit's publications are few in number and very brief, but they show him to have been an original thinker, and his great mechanical skill in working glass enabled him to carry out his designs. His account of the thermometer is of so great interest that I give it entire. "The thermometers constructed by me are chiefly of two kinds, one is filled with alcohol and the other with mercury. Their length varies with the use to which they are put, but all the instruments have this in the degrees of their scales agree with one another and their variations are between fixed limits. The scales of thermometers used for meteorological observations begin below with o and go to 960. The division of the scale depends upon three fixed points which are obtained in the following The first point below, at the beginning of the scale, was found by a mixture of ice, water and sal-ammoniac, or also sea-salt; when a thermometer is put in such a mixture the liquid falls until it reaches a point designated as zero. This experiment succeeds better in winter than in summer. The second point is obtained when water and ice are mixed without the salts named; when a thermometer is put into this mixture the liquid stands at 320, and this I call the commencement of freezing, for still water becomes coated with a film of ice in winter when the liquid in...