APPLIED MECHANICS. igi 



petent to follow the symbolical reasoning of a mathematical 

 treatise. Can it be denied that the principles of mechanics have 

 been understood by those who have shaped and fashioned with 

 their own hands the very subject-matter which gives the science a 

 real existence ? And are we not compelled to admit that the 

 path which these men have opened out so successfully may be 

 safely trod by hundreds of the mechanics of our workshops, who 

 will be enabled, when properly guided, to understand and master 

 the solution of many a problem of engineering, and to comprehend 

 many a complicated piece -of mechanism, with no further aid than 

 that derived from patient thought upon the principles involved, 

 and a careful comparison of the successive steps which have led 

 previous inventors to the complete and final result ? 



One object of the present exhibition is to show the manner in 

 which the discoverer has worked, as well as the materials which 

 he has had at his command, and we may now point to a few 

 illustrations. Every one has heard of the model of Newcomen's 

 engine, which Watt undertook to repair, and King's College lends 

 an original fac-simile of Newcomen's engine. There is also an 

 interesting collection presented by Mr. Gilbert Hamilton, of the 

 Soho Works, near Birmingham, which may serve to. remind us 

 of the progress of Watt's thoughtful labour in giving a substantial 

 form to his conceptions of the separate condenser and the expan- 

 sive working of steam. Little more than a hundred years ago, 

 and the manufacturing industry of this great country was yet 

 unborn, though it was destined to spring into existence as soon 

 as the inventive genius of the great mechanic had divined, with 

 such models before him, a better mode of " directing one of the 

 great sources of power in nature." 



At that time the machine tools for shaping iron were almost 

 inadequate to the construction of a steam-engine. We are told 

 that the piston in Newcomen's engine was made steam-tight by a 

 layer of water on the top of it, and that in Watt's first engine, 

 which had a cylinder of only eighteen inches diameter, it was 



