14 Transactions. — Miscellaneous. 



is essential that a knowledge of these things should be like a 

 second nature. 



Another conventionalism to be reckoned with is the depre- 

 ciation implied in the comparison of theory and practice. An 

 ounce of practice is said to be equal to a ton, I think it is, of 

 theory. If there is any foundation for this at all it must be 

 infinitesimal. Theory which is held so cheap cannot be 

 theory in fact. By theory I mean scientific deduction, and 

 not hypothesis merely. The three angles of any triangle are 

 in theory equal to 180°, but if in actual measurement they 

 amount to more or less, then practice is wrong. If, however, 

 it is held to be theoretically possible that the angles may be 

 so carefully measured with an instrument so absolutely per- 

 fect that they may sum up exactly to the known figure, then 

 practice will show that this theoretical supposition is wrong, 

 and that only by accident can such absolute perfection be 

 attained. An incident in point came under my observation 

 in the Old Country very many years ago. One of the best 

 workmen I ever knew — a foreman fitter — was marking off on 

 a circle the centres of six bolt-holes. As usually happens, 

 the dividers, opened to the radius of the circle, did not, on 

 stepping round, exactly close on the commencing-point. My 

 friend remarked that it never did— that the radius of a circle 

 did not divide the circumference exactly into six, but only 

 very near it. Of course, I said that it was a geometrical fact 

 that such a division w T as exact, but was met with the remark 

 that it might be so in theory, but practice showed the con- 

 trary. 



A good many years ago the Messrs. Denny, of Dumbarton, 

 recognised that among the thousands of their workmen there 

 ought to be much latent talent for the invention of improve- 

 ment in tools and methods of application, only requiring some 

 incentive to bring it into action. The firm accordingly insti- 

 tuted a scheme by which rewards were to be given in pro- 

 portion to merit for any improvement by which time could 

 be saved or better work performed than was possible with 

 previous appliances. This scheme has proved very success- 

 ful, and for many years numbers of important improvements 

 of all kinds, large and small, were the result of an incentive 

 to the use of their heads as well as their hands by men who 

 had nothing to learn in mere workmanship. 



Among those misguided searchers after perpetual motion, 

 of which we have evidence even to this day, there is not 

 one true mechanic. Either they are workmen more or less 

 expert or mere mathematicians, in neither case with any 

 knowledge of or capacity to acquire true mechanics. 1 

 have met several of both classes, and found in all cases 

 their craze incurable. I noticed very latelv that a gentle- 



