Meteorological observations and essays / by John Dalton.

  • Dalton, John, 1766-1844.
Date:
1834
Catalogue details

Licence: Public Domain Mark

Credit: Meteorological observations and essays / by John Dalton. Source: Wellcome Collection.

Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.

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    by philosophers of the present age, without scruple; but people not much versant in philosophical in- quiries admit them with reluctance; they appre- hend, that if bodies were pressed with the force above mentioned, which amounts to about 151bs. avoirdupoise upon each square inch of surface, the effect should be obvious; whereas it is found that bodies of the slightest texture are unhurt by the atmosphere,—and the great facility with which bo- dies are moved in the atmosphere, they conceive as another objection.—Perhaps it may be some help to these to observe, that the atmosphere presses equally upon bodies in every direction, and has therefore no tendency to separate their parts ; and, as for the resistance which bodies meet with in moving through the atmosphere, it is not propor- tionate to the pressure of the atmosphere, but to its density, which being very little, as has been obser- ved above, the resistance is small. The barometer was invented in 1643, by Torri- celli, at Florence, in Italy.—The phenomenon soon attracted the notice of philosophers of that age, and the more so, as it seemed to prove the exist- ence of a vacuum, when the opinion of its non- existence was general, and the maxim that nature abhors a vacuum, was almost unquestioned. Had the quicksilver still continued to fill the tube when erected, the fact would have been accounted for on this imaginary principle, and have passed without further notice. As it was, however, those who