Lectures on select subjects in mechanics, hydrostatics, hydraulics, pneumatics, and optics, with the use of the globes, the art of dialing, and the calculation of the mean times of new and full moons and eclipses / By James Ferguson.

  • Ferguson, James, 1710-1776.
Date:
1803
Catalogue details

Licence: Public Domain Mark

Credit: Lectures on select subjects in mechanics, hydrostatics, hydraulics, pneumatics, and optics, with the use of the globes, the art of dialing, and the calculation of the mean times of new and full moons and eclipses / By James Ferguson. Source: Wellcome Collection.

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    Of Hjdrqflatlcs* 101 LECT. V. Of hydrojiatics, and hydraulic machines. THE fcience of hydrojiatics treats of the nature, gravity, preffure, and motion of fluids in general 5 and of weighing folids in them. A fluid is a body that yields to the Ieafl: pref- Defim- fure or difference of preflures. Its particles are don of a l'o fmall, that they cannot be difcerned by the flllid> bell microfcopes ; they are hard, fince no fluid, except air or fleam, can be (preffed into a lefs fpace tnan it naturally poffefles ; and they muff be round and fmooth, feeing they are fo eafily moved among one another. All bodies, both fluid and folid, prefs down- ward by the force of gravity: but fluids have this wonderful property, that their preffure up- ward and fide wile is equal to their preffure down- ward ; and this is always in proportion to their perpendicular height, without any regard to their quantity j for, as each particle is quite free to move, it will move toward that part or fide on which the preffure is leaft. And hence, no par- ticle or quantity of a fluid can be at reff, till it is every way equally preffed. ' ny eTriment 'hat fluids prefs up-Hate X S tl11 JS let A B 1* lone Fig. andC fl , f t ,Wh Water near t0 its lop'; Flll;d and c D a fmall tube open at both ends and prcftas immerfed into the wntpr irr n 1 as? an<d much up- immerfion Z ‘ / Z ' ‘l16 larSe one J if 'he ward J in rhp f n ,1 l( h> you will fee the water rife down- in t ™ ‘° ,he &T heiSht 'hat it fiand-1' ' great one’ until the furfaces of the