ADVERTISEMENT. 
The work of Tredgold on the Steam Engine, from its first appearance 
in the year 1827 up to the present time, has maintained the highest 
reputation, both in this country and on the continent. Since the pub 
lication of the first edition, the boundless resources of steam power 
have been directed, on the most enlarged scale, to almost every im 
portant purpose of mankind, and the steam engine has achieved the 
greatest triumphs of human ingenuity. The present edition contains 
several valuable contributions from professional gentlemen of acknow 
ledged ability and experience; and, with these and the many revisions 
and additions which the work has undergone, it is hoped that it will be 
found suited to the present advanced state of the science, and that it 
may continue to occupy the same favorable position which it has hitherto 
enjoyed. A considerable number of errors have been corrected which 
appeared in the first edition ; and, amongst many other improvements, 
the principles of parallel motion, so important to the manufacturer, 
have been put in a complete form. 
The Appendix consists of the following original papers : 
I. On the practical nature and general management of marine boilers, 
by Mr. Dinnen.