446 THE POPULAR SCIENCE MONTHLY. 



THE GKOWTH OF THE STEAM-ENGINE. 1 



By Pkofessoe E. H. THURSTON, 



OF THE STEVENS INSTITUTE OF TECHNOLOGY. 



IV. 



STEAM-NAVIGATION. 



72. Among the most interesting of the applications of steam- 

 power, to the political economist and to the historian, as well as to 

 the engineer, is its use in ship-propulsion. 



In the modern marine engine we find one of the most important 

 adaptations of steam machinery and the greatest of all the triumphs 

 of the mechanical engineer. 



Although, as has been already stated in previous lectures, at- 

 tempts had been made, before the beginning of the present century, 

 to successfully effect this application of the power of steam, they did 

 not succeed, in any instance, as commercial enterprises, until after 

 that date. 



Indeed, it is but a few years ago that the passage across the At- 

 lantic was made by sailing-vessels almost exclusively, and that the 

 dangers, the discomforts, and the irregularities of their trips were 

 most serious. 



Now, hardly a day passes that does not see several large and 

 powerful steamers leaving the ports of New York and Liverpool to 

 make the same voyages ; and their passages are made with such regu- 

 larity and safety that travelers can anticipate, with confidence, the 

 time which will mark the termination of their voyage, predicting the 

 day and almost the hour of their arrival, and can cross with safety 

 and comparative comfort, even amid the storms of winter. 



Yet, all that we to-day see of the extent and the efficiency of 

 steam-navigation has been the work of the present century ; and it 

 may well excite both our wonder and our admiration. 



73. The history of this development of the use of steam-power 

 illustrates, more perfectly than any other, that process of the growth 

 of this invention which has been already referred to. We can here 

 trace it, step by step, from the earliest and rudest devices up to those 

 most recent and most perfect designs, which represent the most suc- 

 cessful existing types of the heat-engine whether considered with 

 reference to its design and construction, or as the highest application 

 of known scientific principles that have yet been found attainable in 

 even the present advanced state of the mechanic arts. 



74. This application of the force of steam was very possibly anti- 



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

 by D. Appleton & Co. 



