22d Day. The Air-Pump; the Instruments for Condensing and Transferring of Air; their Fabrick, Operation, and Gages explained. 23d—A Parcel of Air weighed in the Balance; its Specifick Gravity to that of Water determined thereby; an artificial Storm, shewing that high Winds may make the Barometer sink much and suddenly. 24th—The Weight, Pressure, and Spring of the Air prov'd several ways; by the Sense of Feeling; by breaking Glass Vials; the Phænomena of Bladders, Glass-bubbles, Fountains; the Gardiner's Watering-Pot; the Diving-Bell, _&c._ 25th—The Torricellian Tube _in Vacuo_; Quicksilver raised to the usual Height of the Weather-Glass, by the bare Spring of a little included Air; _Otto Gerick_'s Hemispheres; and that dense Air has the same Advantage over common Air, as that has over a _Vacuum_. The Ebullition of Liquors _in Vacuo_; the Quantity of Air contain'd in them; the Sustentation of Fumes and Vapours; the Descent of Bodies _in Vacuo_. _The more hidden Properties of the Air consider'd by the help of the like Engines._ 26th Day. The Influence of the Air examin'd as to the Causes of Magnetism; the Elasticity of Springs; the Cohæsion of the Parts of Matter; the Sphericity of the Drops of Fluids; the Ascent of Liquors in capillary Tubes, and between Glass-Planes in the Curve of the Hyperbola, both by the Attractive and Repulsive Power of the Glass. 27th—The Influence of the Air, as to Sounds, Fire, and Flame; the Consumption of Fuel; the firing of Gunpowder; the Effects of rarified, condensed, and burnt Air upon the Life of Animals. 28th—A Piece of Phosphorus _in Vacuo_; new Experiments concerning the Mercurial Phosphori; Experiments concerning the Electricity of Bodies. -------------------------------------------------------------------------- _Every SUBSCRIBER is to pay Three Guineas; One Guinea at the Time of Subscription, and the Remainder, the First Day of the Course._ SUBSCRIPTIONS _are taken in at Mr. Whiston's, in Great Russel-Street; and at Mr. Hauksbee's, in Crane-Court in Fleetstreet; where the Course is to be perform'd._ Advertisement.