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 / [James Ferguson].

James Ferguson

Date:: 1790

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 / [James Ferguson]. Source: Wellcome Collection.

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$water will be raifed from % to ¢ in the tube; three times as hich above the bottom as when it began to appear in the tube at g; which fhews, that the fame quantity of water that prefied, but with the force of one pound on the bottom, when raifed no higher than a, prefies with the force of three pounds on the bottom when raifed three times as high to ¢ in the tube. Put a-fourth pound weight into the {cale, and it will caufe the water to rife in the tube from ¢ to d, four times as high as when it was all contained in the box, which fhews that its preffure then upon the bottom is four times as great as when it lay all within the box. Put a fifth pound weight into the feale, _ and the water will rife in the tube from d to e, five times as high as it was above the bottom before it rofe in the tube; which thews that its preffure on the bottom is then equal to five pounds, feeing that it fupports fo much weight in the fcale.. And fo on, if the tube was ftil] longer; for it would ftill require an additional pound put into the fcale, to raife the water in the tube to an additional height equal to the {pace de; even if the bore of the tube was fo {mall as only to let the wire move freely within it, and leave room for any water to get round the wire, Hence we infer, that if a long narrow pipe or tube was fixed in the top of a cafk full of liquor, and\if as much liquor was poured into the tube as would fill it, even though it were fo {mall as not to hold an ounce weight of li- -quor; the preffure arifing from the liquor in the tube would be as great upon the bottom, BA: 3 and$