A Course of Mechanical, Magnetical, Optical, Hydrostatical and Pneumatical Experiments / perform'd by Francis Hauksbee, and the Explanatory Lectures read by William Whiston, M.A.

by William Whiston; Francis Hauksbee

Fig. 5. Is the whole Apparatus of the Hydrostatical Balance. The Glass Bubble G is heavier than all Fluids but Quicksilver, and is to be put into all those Fluids: The Bulk of Water in ours is 830 Grains Troy. If when pois'd in Water it sink more by any Number of Grains, that Number of Grains substracted from; if less, added to those 830, do by their Proportion to 830 give the Specifick Gravity of all such Fluids to Water. I K is the Glass Bucket, which in Air is in Æquilibrio with the Scale E: And because when it is let into Water, it will be no longer an Equipoise to the opposite Scale, but lighter; the Scale R is to be added to the Part H, by which the Bucket is suspended, and that will restore the Æquilibrium in Water. By this Solids and Quicksilver are weighed first in Air, and then in Water: The Difference of which Weights being the Weight of an equal Bulk of Water, by its Proportion to the first Weight in Air, gives the Specifick Gravity of the Solid compared with Water: And if that Difference still divide the Weight in Air, for all sort of Bodies, we may have a Table of the Specifick Gravities of the Solids; as by dividing 830 by the Sum or Difference of the other Fluids, we may have a like Table of the Specifick Gravity of Fluids, such an one as here presented the Reader.

HYDROSTATICKS.
A TABLE of the Specifick Gravities of several Solid and Fluid Bodies.

Fine Gold 19,640 Standard Gold 18,888 Quicksilver 14,000 Lead 11,325 Fine Silver 11,091 Standard Silver 10,535 Bismuth 9,700 Copper 9,000 Cast Brass 8,000 Steel } Soft 7,738 the same } Hard 7,704 Piece } Spring Temper 7,809 Iron 7,645 Tin 7,320 Glass of Antimony 5,280 A Pseudo Topaz 4,270 A Diamond 3,400 Clear Crystal Glass 3,150 Iceland Crystal 2,720 Fine Marble 2,700 Rock Crystal 2,650 Common Green Glass 2,620 Stone of a mean Gravity 2,500 Sal Gemmæ 2,143 Brick 2,000 Nitre 1,900 Alabaster 1,875 Dry Ivory 1,825 Brimstone 1,800 Dantzick Vitriol 1,715 Allom 1,714 Borax 1,714

Calculus Humanus 1,700 Oyl of Vitriol 1,700 Oyl of Tartar 1,550 Bezoar 1,500 Honey 1,450 Gum Arabick 1,375 Spirit of Nitre 1,315 Aqua Fortis 1,300 Serum of Human Blood 1,190 Pitch 1,150 Spirit of Salt 1,130 Spirit of Urine 1,120 Human Blood 1,040 Amber 1,040 Milk 1,030 Urine 1,030 Dry Box-Wood 1,030 Sea-Water 1,030 Common Water 1,000 Camphire 0,996 Bees-Wax 0,955 Lynseed Oyl 0,932 Dry Oak 0,925 Oyl Olive 0,913 Spirit of Turpentine 0,874 Rectified Spirit of Wine 0,866 Dry Ash 0,800 Dry Maple 0,755 Dry Elm 0,600 Dry Firr 0,550 Cork 0,240 Air 0,001 ¼

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PNEUMATICKS.

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An Explication of the First Plate.

Figure 1. Are several Torricellian Tubes or Barometers of different Shapes, Bores, and Positions; but where the perpendicular Altitude of the Quicksilver in the Tubes, above the Level of the Surface of that in the Bason, is ever the same, or between 28 and 31 inches high; which is the known Counterpoise between 32 and 36 Feet of Water; and to the entire Atmosphere in its several States and Elevations, where the Bases or the several Tubes are supposed equal.