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SCIENCE. 



[N. S. Vol. VII. No. 167. 



appliance whereby the principle might be 

 utilized. But here, as elsewhere, the work 

 of discovery and that of invention went on 

 almost pari passu; the results of each in- 

 creased those of the other. The distance 

 fiom the Clark and Page machines of the 

 middle thirties, with their cumbrous horse- 

 shoe magnets and disproportionate ex- 

 penditure of power, to the Siemens machine 

 of the fifties was long ; but it was no leap. 

 In like manner, slow steps marked progress 

 thence to the Gramme machine, in which 

 one finds the outgrowth of many years of 

 labor by many men, both investigators and 

 inventors. In 1870, forty years after 

 Faraday's announcement of the basal 

 pi'inciple, the stage was reached whence 

 progress could be rapid. Since that time 

 the dynamo has been brought into such 

 stage of efficiency that the electro motor 

 seems likely to displace not merely the 

 steam engine, but also other agencies in 

 direct application of force. The horse is 

 passing away and the trolley road runs 

 along the country highway ; the longer rail- 

 ways are considering the wisdom of chang- 

 ing their power; cities are lighted brilliantly 

 where formerly the gloom invited highway- 

 men to ply their trade; and even the kitchen 

 is invaded by new methods of heating. 



Long ago it was known that, if the refin- 

 ing of pig iron be stopped just before the 

 tendency to solidify became pronounced, 

 the wrought iron is more durable than that 

 obtained in the completed process. Thus 

 imperfectly refined metal was made fre- 

 quently, though unintentionally and igno- 

 rantly. A short railroad in southwestern 

 Pennsylvania was laid in the middle sixties 

 with iron rails of light weight. A rail's life 

 in those days rarely exceeded five years ; 

 yet some of those light rails were in excel- 

 lent condition almost fifteen years after- 

 wards, though they had carried a heavy coke 

 traffic for several years. But this process 

 was uncertain, and the best puddlers could 



never tell when to stop the process in order 

 to obtain the desired grade. 



"When a modification of this refining 

 process was attempted on a grand scale 

 almost contemporaneously by Martien in 

 this country and Bessemer in England the 

 same uncertainty of product was encoun- 

 tered ; sometimes the process was checked 

 too soon, at others pushed too far. Here 

 the inventor came to a halt. He could use 

 only what was known and endeavor to im- 

 prove methods of application. Under such 

 conditions the Bessemer process was appar- 

 ently a hopeless failure. Another, how- 

 ever, utilized the hitherto ignored work of 

 the closet investigator. The influence of 

 manganese in counteracting the effects of 

 certain injurious substances and its relation 

 to carbon when present in pig iron were 

 understood as matters of scientific interest. 

 Mushet recognized the bearing of these 

 facts and used them in changing the pro- 

 cess. His method proved successful ; but, 

 with thorough scientific forgetfulness of the 

 main chance, he neglected to pay some 

 petty fees at the Patent Office, and so 

 reaped neither profit nor popular glory for 

 his work. 



The Mushet process having proved the 

 possibility of immediate and certain con- 

 version, the genius of the inventor found 

 full scope. The change in form and size 

 of the converter, the removable base, the 

 use of trunnions and other details, largely 

 due to the American, Holley, so increased 

 the output and reduced the cost that Bes- 

 semer steel soon displaced iron and the 

 world passed from the age of iron into the 

 age of steel. 



Architectural methods have been revolu- 

 tionized. Buildings ten stories high are 

 commonplace ; those of twenty no longer 

 excite comment, and one of thirty arouses 

 no more than a passing pleasantry respect- 

 ing possibilities at the top. Such buildings 

 were almost impossible a score of years ago, 



