THE 



POPULAR SCIENCE 

 MONTHLY. 



JANUARY, 1878, 



THE GROWTH OF THE STEAM-ENGINE. 1 



By Professor E. H. THURSTON, 



OF THE STEVENS INSTITUTE OF TECHNOLOGY. 

 III. 



THE NON-CONDENSING ENGINE, AND ITS APPLICATION IN THE 



LOCOMOTIVE. 



45. The engines of 

 Hero and Branca were, 

 it will be remembered, 

 non-condensing; but the 

 first plan of a non-con- 

 densing enp-ine that 

 could have been made of any really practical use is given in the 

 "Theatrum Machinarum" of Leupold, published in 1720. His sketch 

 is copied in Fig. 23. It is stated by Leupold that this plan was sug- 



1 An abstract of " A History of the Growth of the Steam-Engine," to be published 

 by D. Appleton & Co. 



VOL. XII. 17 



