Pneumatics.

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f °ne of

e of the common Air-pump, anda new Invention of my own.

The

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fha^ by Experience : And I believe a better

^ ’■bis was never made.

°^ e j In the Construction of my Aerometrum Mag-Tlj e ° r Tripple Weather-Glass, 1 have a Barometer,anc ‘ Hygrometer all in one Frame ; all ofly , Sort; which makes a Piece of Furniture equal-’&U»delcp„,

ticjWV) i. There remains yet one more Pneuma-5b| e \ T c ^’ ne to be described, which has made consiaer-be Cri ^oise in the Philosophic World, but has neverWi

e nt:

^ any Use in Civil Life ; I mean, the famous■ lQ n of the Air-Gun, of which there are two

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ii'i, e ’ one the Common Air-Gun , the other the Maga-. Of both which I shall give the follow-

iti

t^n :

3 . ^ Account.

Jjas *, le Common Air-Gun is made of Brass, and«o re Barrels; the Inside Barrel K A. of a small^hel ^ rotn w bich the Bullets are shot; and a largerSy f j 1 E C D R on the Outside of it. There is aHj c jp SJV1NP fixed in th? Stock of the Gun, by\ p me Air is injected into the Cavity between thePut d aa rrel s _ through the Valve E P. The Ball K is’ nto ’ ts P' ace i n t b e small Barrel with theHi^ ^ - as * n another Gun. At S L is another Valve,^e^j r ° e ‘ n g drawn open by the Trigger O, permits^ tQ come behind the Bullet, to as to drive it out3 ^ Force.

^’ s Valve be open’d and shut suddenly, onecondensed Air may make several Dischargesj a gl e > but. if the whole Air be discharged on one}V c Hai- U . ’ ^ will drive it out more forcibly. This' s effected by means of a Lock k / placedVs’ n other Guns; for the Trigger beingjj'st will 6 ^ock k will go down, and drive a Lever a,^ o?cn the Valve, and let in the Air upon the

4 . The