CONTENTS.

Of Farenheit’s Mercurial c fhermo?neter >

ibid.

The Nature • and Use of a Standard Thermo-meter exemplified, 183, 184

The Newtonian Scheme of Degrees ofHeat , from Freezing to that of Fire.,

185, 186

Dr. Hales’s Thermometer for Hot-Beds,

186

The Nature <W‘Theory o/~ /A? Hygrometer,

187

The beft Way of making them , 188

The Theory of the common Air-gun, 189Of Colbe’s Magazine Air-Gun, 190 192

The Theory and Structure of the Air-Pump,

188—193

Of a New Portable Air-Pump of the Au-thor’s Invention , 193—19 5

Of the Rarefaction of the Air in the Recipientby Calculation , 195—198

Of the Gage of the Air-Pump and .Con-denser, 198