Essays and observations on the construction and graduation of thermometers, and on the heating and cooling of bodies / By George Martine.

  • George Martine
Date:
1772
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Licence: Public Domain Mark

Credit: Essays and observations on the construction and graduation of thermometers, and on the heating and cooling of bodies / By George Martine. Source: Wellcome Collection.

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    fideration, what if the real folar heat both in itfelf, and what it can communicate to us, and other pla- netary bodies (while it is not concentrated by burn- Ing glafles, or ftrengthened by other affiftances) be-vaitly lefs than what is commonly reckoned ? All the natural heat we meet with here on the earth we are ready to afcribe tothe aétion of the Sun, which perhaps has but a fimall fhare in it, o- _ verlooking a fource of heat, which, though often fpoke of by the Theorifts of the Earth *, is fel-. dom confidered in that advantageous light I would’ choofe to take it. We formerly took notice of what a great ftock of heat all terreftrial bodies are pofleffed, even in the coldeft winters. Every body has felt or heard that the temperature of the air in mines and other places deep under ground is warm, or at leaft very tolerable. And we know, from the niceft obfervations, that in the cave of the ob- fervatory at Paris, only about go feet under sround, the heat keeps the Thermometer at gr. $3; and that without any afliftance from the Sun; it being never fenfibly increafed by the moft- * See Empedocles in Plutarch. de Prim. Frigid. p. m. 507. Des Cartes Princip. Phil IV. 3, - Burnet Theor. of the Earth. 11]. 6. Woodward Eff. Nat. Hit. of the Earth. p, ~135—162. 220-205. -Nage iif, &e. illuftr, &c, Introd. p. 136. 149.——143. 149—~152- Whilton New Theor. &c. p. 78. 231, 334-447. Gaillend. Epicur, Philofoph. I, p. 546, &e, fcorching