Analysis of a course of lectures : on mechanics, hydrostatics, pneumatics, and astronomy / read by James Ferguson.

  • James Ferguson
Date:
1761
Catalogue details

Licence: Public Domain Mark

Credit: Analysis of a course of lectures : on mechanics, hydrostatics, pneumatics, and astronomy / read by James Ferguson. Source: Wellcome Collection.

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    On » [ *2 ] HYDROSTATICS. FLUIDS prefs equally in all manner of direc¬ tions, as is {hewn by their motions in four glafs tubes, open at each end j one tube being quite ffraight, another bent diredly upward at the lower end, a third bent lidewife to a right angle, and the fourth bent obliquely. All thefe being put in water near to their tops, the water rifes in each of them to a level with the furface of that in which they are immerfed. If a piece of lead, whofe upper lide is fiat, be put into an empty veffel; and a piece of wood, whofe under fide is flat, be put upon the lead, fo as no water may get between *, and the wood be held down till the veffel be filled with water, the wood will remain upon the lead at bottom: for it is then kept down both by its own weight, and the weight of the water above it •, the upward preflfure of the water being prevented, as none gets in between the lead and the wood. If a wide tube, open at both ends, has a piece of lead held dole to its lower end, by a firing within the tube, fo as no water can get between the lead and the tube; and then, if the whole be immerfed in water, till the depth of the lead below the furface of the water in the veffel be almoft twelve times the thicknefs of the lead, the firing may then be let go *, for the lead will not fall away from the tube, becaufe the upward preffure of the water is greater than the weight of the lead •, and no water gets above it to prefs it down.—But if the tube and lead be raffed, till •the depreffion of the lead below the furface of the water in the veffel be any thing lefs than 1times the thicknefs of the lead, it will then fall off: which {hews, that lead is i i-J- times as heavy as its bulk ofl water, * .. Ifi
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