_Fig. 9._ Is the new Sort of Cupping-Glass, whence the Air is suck'd out by a Syringe, and where by a Valve it is hindred from returning. _Fig. 10._ Is an Example of Suction; and will shew that Quicksilver can thereby never be rais'd to 29½ Inches. _Fig. 11._ Is an Example of a Weight raised by a Syringe, as Water uses to be; and still shews, that all is proportionable to the Power of the Air's Pressure, and is limited thereby. [[Plate II. ― I. Senex sculp.^t]] PNEUMATICKS. 16 An Explication of the Second PLATE. Figure 1. Is the Air-Pump, with its Receiver and Gage, as ready for Use; _a a_, _a a_ are two strong hollow Cylindrical Barrels, in which are suppos'd to be Suckers, with their Handles _c c_, _c c_ notched; into which Notches a Cog-wheel falls, which Cog-wheel moves upon the Axis _f_, when the Engine is put into Motion by the Winch _b b_. _g g_, _g g_ are two Cylinders of Wood, fixed to the Frame of the Air-Pump, with Screws at the Top, on which the Nuts _e_, _e e_ do run, and press down the upper Piece _f f_ upon the Tops of the Brass Barrels, to fix them both at Top and Bottom. _h h_ is a Swan-neck'd, or small bended hollow Brass Pipe, leading from the Top-Plate _i i i i_, or rather from the Brass hollow Piece above _n n_, which communicates through that Top-Plate with the Cavity of the Receiver. This Pipe is screwed to a bottom Brass Piece, included in the Box _d d_; which is perforated not only lengthways, but also upwards, in three Places: The Middle one for a Communication with this Swan-neck'd Pipe, and at the two Ends through small Cylinders; inserted into the two Brass Barrels _a a a a_; and 'tis by this Threefold Communication, that the Air is pump'd out of the Receiver. _l l l_ is the Gage; which is no other than a common Barometer, or Weather-Glass; with its Bason of Mercury _m m_, fix'd to the Engine by a particular Contrivance, and its Index or Boxen Receptacle, with Inches, and its Cork to support that Index upon the Surface of the Mercury, and to rise and fall with it; for the Exactness of measuring the Height of the Mercury from that Surface. Only this Barometer is open at the Top, and communicates, as does the Swan-neck'd Pipe, with the Cavity of the Receiver. _n n_ is a Stop-cock, that communicates also with the Cavity of the Receiver, and either excludes or readmits the Air, as you see convenient. _k_ is the Bottom of the Receiver, ground true to fit the Brass Circle below it; to which it is affixed by the Hand at first, and afterward by the Pressure of the Air, with wet Leather instead of Cement.