John Dollond, Edward Somerset 99 



satisfaction of solving, at last, this most important problem. 

 By combining two lenses of different kinds of glass, he could 

 produce images in which the colour defect was, though not 

 entirely abolished, yet very materially diminished. In this 

 discovery he was, however, anticipated by Chester More 

 Hall of More Hall in Essex, a barrister, who, in 1833, had 

 already succeeded in constructing an achromatic lens. 

 Dollond's patent was subsequently challenged on the ground 

 of anticipation, but the judgment was upheld in favour of 

 Dollond on the ground containing much common sense 

 that " it was not the person who locked his invention in his 

 scrutoire that ought to profit from such invention, but he 

 who brought it forth for the benefit of mankind." 



The improvements effected in electrical appliances by 

 Canton, Henley, Bennett and others have already been 

 described, and we may therefore pass on to the more direct 

 applications of scientific principles to the utilization of power. 

 The early steam engines we should hardly call them by 

 that name now were little more than toys, useful, perhaps, 

 for the special purpose for which they were designed, but 

 wasteful and costly in their working. It was only when 

 James Watt came to apply the scientific methods acquired 

 in his intercourse with Joseph Black and John Robison 

 that an efficient machine could be evolved. 



We may begin our account of the history of steam 

 engines with Edward Somerset, Marquis of Worcester, 

 whose romantic personality and tragic history form an 

 interesting study. He claims to have accomplished some 

 wonderful things in a publication that bears the eccentric 

 title : "A century of the names and skantlings of such 

 inventions as at present I can call to mind to have tried 

 and perfected, which, my former notes being lost, I have 

 at the instance of a powerful friend endeavoured, now in 

 the year 1655, to set down in such a way as may sufficiently 

 instruct me to put any of them in practice." But his 

 descriptions are so fantastic and vague that doubts have 

 been raised whether he had ever gone beyond the forming 

 of plans and making of projects, leaving the rest to his 

 imagination, which had ample scope to exercise itself 

 during a six years' confinement in the Tower of London. 



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