38 On Mechanical Science. 



the variation in the rate to this cause, or an imperfect com- 

 pensation. Since (as has been observed before) a pendulum 

 of deal may be made constant under all the vicissitudes of the 

 seasons, thei'e is therefore nothing remaining but to render 

 the arc of vibration also constant, with a given maintaining 

 power in all cases of atmospheric influence ; and then we shall 

 be able to give to that useful machine the clock, that equable 

 motion which constitutes its intrinsic value, for measuring 

 time with accuracy. I remain. Gentlemen, 



most respectfully yours, 

 Epping, Dec. 14th, 1826. Thomas Squire. 



VII. On Mechanical Science* 



TT is a very common opinion that there is an essential diffe- 

 -^ rence between the principles of Geometrical and of Mecha- 

 nical science. The former is supposed to be independent of 

 matter, the latter to be entirely dependent on it. Geometrical 

 science is imagined to be derived without aid from experience, 

 while mechanical science is said to be founded wholly on ob- 

 servation and experiment. These notions appear to have had 

 much influence in retarding the progress of pure science, by 

 limiting its extent, and causing the important doctrines of me- 

 chanics to be mixed with matters of mere observation ; that 

 is, instead of a general and unlimited investigation of the re- 

 lations that might exist among forces, times, and spaces, it is 

 confined to those relations only which are observed to take 

 place in the ordinary natural phaenomena ; a few cases ex- 

 cepted, which are evidences of the general nature of the science. 



In no instance have I seen a more distinct announcement 

 of this narrow opinion regarding mechanics than in the ex- 

 cellent discourse which commences the " Library of Useful 

 Knowledge" now publishing for the diffusion of science, and 

 having an equal feeling of interest for the progress of pure 

 and of practical science. I shall not scruple attempting to 

 show that those opinions, which are not peculiar to that work, 

 are not perfectly correct. 



It will be admitted that an idea of a third dimension is ne- 

 cessary to geometry. Now I contend that the mind cannot 

 obtain this idea without a previous one of power ; and that it 

 is simply power acting unresisted, which gives us our know- 

 ledge of space as being bounded by a figure of three dimen- 

 sions. Deprive the mind of the aid of power, and it must be- 

 come wholly incapable of conceiving the idea of space, or 

 figure of three dimensions ; for the organ of sight gives no 

 • Communicated by the Aiitlior. 



aid 



