APPLIED MECHANICS. 189 



the final conclusion, has come to be regarded as so indispensable 

 that no system of abstract thought is received with favour so long 

 as it is not linked with and supplemented by minute observation 

 of the constructive work to which it is related. 



Many now living can look back upon the time when a broad 

 line of separation existed between the theoretical and practical 

 mechanician. The former passed his life in the seclusion of the 

 academical retreats of our universities, and thought and pondered 

 and built up a system of study with but little care or regard for 

 the work that was being drone by engineers in the world around 

 him, scarcely thinking, perhaps, that it was necessary that the 

 master who had assumed to write for the teaching of others should 

 concern himself with such things as the production of a true plane 

 surface, or the power of measurement, or the invention of machinery 

 for planing iron, or making paper, or printing newspapers, or 

 combing wool, or spinning cotton. 



It is interesting to turn to the mechanical treatises written 

 under the old system, and to note that they are to the full as 

 barren and unprofitable as might reasonably have been antici- 

 pated from the method on which they proceeded. In style and 

 manner they are faultless ; as examples of logical reasoning by 

 symbols they cannot be surpassed ; they are full of problems the 

 solution of which demands the highest mathematical skill and 

 aptitude; but unhappily they are the work of men who have 

 remained passive in their own libraries, who have laboured only 

 by the light of their own imagination, who have never seen a pier 

 founded, or a bridge built, or a steam-engine made, and who have 

 considered themselves competent to teach the most practical of all 

 sciences without becoming in any way acquainted with its practice. 

 The result has been that the mechanics of the schoolmen has 

 assumed another and a different form from that by which it is 

 recognised among the mechanicians and engineers who have 

 given us our railways, our steamships, and our telegraphs, and 

 have filled our factories with machinery for supplying all our 

 varied wants. 



