75 



THE POPULAR SCIENCE MONTHLY. 



and tracing the slow stages of its progress, 

 we may take its condition at any time as 

 indicating the progress in man's knowledge 

 of the laws of Nature. It has grown with 

 the growth of science and the advance of 

 the human mind. 



It was known thousands of years ago 

 that, when fire is applied to water, vapor 

 is formed that is capable of producing me- 

 chanical effects, and centuries before the 

 Christian era attempts had been made to 

 use this force in impelling a machine. The 

 revolving.<Eolipyleof Hero, the Alexandrian, 

 was a toy for a thousand years. During 

 the middle ages many a mechanical genius 

 played with it, but in vain, for there was no 

 knowledge, and consequently there were 

 no valuable results and no progress. 



With the modern awakening of inquiry 

 the subject was pursued by many ingenious 

 experimenters, in different countries and at 

 different times, until at the beginning of the 

 eighteenth century so much had been found 

 out about the properties of heat, water, and 

 air, and so many devices had been hit upon 

 to apply them, that it became possible to 

 combine the different elements into a steam- 

 machine that could perform work. Newco- 

 men's engine of 1705 embodied the ideas 

 and artifices that had been previously 

 gained, and, though very imperfect, was still 

 available for useful mechanical effects. The 

 steam-engine then first became a fact and a 

 success. 



From this time onward, to the patenting 

 of Watt's double-acting engine in 1769, was 

 a period of great activity in improving and 

 developing the machine. Scientific research 

 led the way in working out chemical and 

 physical principles, and inventors were busy 

 in perfecting and combining contrivances 

 which were crowned by James Watt, who, 

 by introducing the principles of separate 

 condensation and double-action, gave to the 

 steam-engine it's modern form and made it 

 available for innumerable applications. 



After Watt's great success we have a 

 hundred years of still further improvements 

 and refinements in the mechanism, and an 

 enormous extension of its uses. From a 

 contrivance supposed to be mainly valuable 

 for pumping water, it became a universal 

 motor equally valuable for manufacture and 

 for locomotion on sea and land. 



But, though it has been greatly per- 



fected, the steam-engine is confessedly still 

 imperfect. It has been undergoing steady 

 improvement in recent years, and its theory 

 is now so well understood, through the re- 

 fined elucidations of physical research, that 

 the pathway of future improvement is clear- 

 ly discerned by sagacious engineers. 



The history of the growth of this remark- 

 able mechanism, that has now become so 

 potent in the operations of human society, 

 has an epic interest of grander meaning than 

 can be found in any history of those de- 

 structive spasms in society that are sung 

 and celebrated as war. The steam-engine 

 is a triumph of peace, a victory of the pa- 

 cific and constructive agencies of civiliza- 

 tion, a conquest of Nature through the pur- 

 suits of science, and a symbol of the rise of 

 modern industrialism and its successful con- 

 flict with the malign military spirit by which 

 the world has been scourged through all the 

 past. 



Prof. Thurston has therefore chosen a 

 theme of great interest in writing the his- 

 tory of the steam-engine, and it has not 

 suffered in his hands. He has done admi- 

 rable justice to its large and varied ele- 

 ments. The principles involved in the 

 mechanism at all its successive stages are 

 analyzed and stated with clearness, and the 

 numerous contrivances and constructions by 

 means of which the steam-engine has been 

 built up and adapted to various ends are 

 plainly, perspicuously, and fully described. 

 The characters, circumstances, and labors, 

 of the great men who have had a share 

 in producing it are pleasantly sketched, 

 and the narrative is enriched by anecdotes 

 and personal episodes that relieve and en- 

 liven the more serious discussions of the 

 book. Solidly instructive throughout, it is 

 at the same time most agreeable reading, 

 while many of the narrative parts are spir- 

 ited and exciting. 



Nothing further needs to be said to the 

 readers of The Popular Science Monthly 

 respecting the merits of Prof. Thurston's 

 work, as they are already acquainted with 

 them through portions of it which have ap- 

 peared in these pages during the past year. 

 One feature of the book, however, deserves 

 especial recognition, and that is the elegance 

 and profusion of its illustrations. In this 

 respect no popular work upon the subject 

 has ever appeared that can at all compare 



