144 POPULAR SCIENCE MONTHLY. 



Steam is apparently coming, as the various other motor-fluids are, 

 into use on the highway, and, after an interregnum of a half -century or 

 more, due to the stupidity of legislators mainly, the automobile, in in- 

 numerable forms and on innumerable 'systems,' is once again displacing 

 the horse in city streets and, in less degree, perhaps, on country roads, 

 and is promising ere long to do a large part of our transportation of 

 merchandise over short routes and off the line of the railway. Thou- 

 sands are now in use in this country and abroad, and tens — hundreds, 

 nominally — of millions of dollars are invested in their manufacture. 



In infinite variety the progress of invention thus reveals itself. In- 

 dividuals, nations, even continents and worlds have courses like that of 

 the rocket : rising with rapid acceleration, upward and onward, to a cul- 

 mination, when a sudden development of energy from latent form 

 occurs, and a brilliant illumination for the moment surprises and en- 

 lightens us; then the limit is attained, the path curves over and down- 

 ward, and after a brief period, downward acceleration begins and its 

 career presently comes to an end. This is not the history of invention, 

 which is never self -limited; a step made is never retraced. The progress 

 of the day is not only recorded in written and printed history and per- 

 manently preserved, but is given a still more permanent record in the 

 life and habits and traditions of the people, and each invention and each 

 new advance is the basis of a later and still higher progress. The only 

 limit to be expected to this advancement of civilization, through inven- 

 tion and the mechanic arts, is that set by some catastrophe which shall 

 ultimately involve the life of the race, having its source in natural evo- 

 lutions of a physical character, and bringing to an end all the activities 

 of mankind in some probably far-distant generation. 



The extent to which the specialization consequent upon the changes 

 in the mechanism and methods of manufactures have progressed during 

 the century just past, may be realized more fully when it is understood 

 that, for example, in the making of a watch, there may be fifteen or 

 sixteen hundred operations conducted with the help of five or six hun- 

 dred machines by as many operatives, each of whom necessarily acquires 

 wonderful expertness in tasks thus repeated constantly, hour by hour, 

 day by day, throughout the working day and the calendar year. These 

 movements become intuitive and automatic; their accuracy and rapidity 

 become almost incredible, and the human machine, through its internal 

 automatism, thus relieves the mind and gives it freedom from stress 

 and fatigue in a manner unknown to the worker of earlier days. The 

 labor-assisting machinery also thus enables the operative to produce, 

 without serious toil and fatigue, from ten to a hundred times as much 

 of his special product as could his unaided predecessor in the vocation 

 with, however, more concentrated attention giving far less skill and ac- 

 curacy. The inventor and the mechanic thus illustrate the immense 



