CONTENTS.

A more particular Calculation of the Force ofWind upon the Sails of a Mill, 211—217A Theory of Mr. T iu ewald’s new WaterBellows, 218, 219

O/SOUNDS*

Of Sounds in generals and how produced.',

212-—219

Of the Make and Structure of the Far, andits several Parts described , 219—224

Of the Tremors of Sounding Bodies,

220—226

The Newtonian Theory of Vibration ofElastic Strings, &c. 225, 228

Of the Waves of Water compared with theVibrations of the Cycloid, 228—231

Of the various Properties of Aerial Pulses orWaves of Air, 230—237

Of the Distance to which Sounds are audible,by Experiments, 232, 23Z

Of the Velocity of the Pulses a priori, 234The fame by Calculation , 235

Experiments to ascertain the fame , 236—241The Nature and Theory of Echoes explained,

241, 242