ADVERTISEMENT. THE Drawings for several of the Cuts in this Volume have been taken, by the permission of Mr. Weale, from the admirable Plates annexed to the last edition of Tredgold on the Steam Engine and on Steam Navigation. This acknowledgment is especially due for the Illustrations which abound in this Volume. London, June, 1840. Accidental Discovery of Condensation by Injection Potter's Discovery of the Method of working the Valves Advantages of the Atmospheric Engine over that of Savery 73 |