RELATIONS. 176 



CHAPTER XV. 



RELATIONS. 



When several different parts contribute to one effect, or, 

 which is the same thing, when an effect is produced by the 

 joint action of different instruments, the fitness of such parts 

 or instruments to one another for the purpose of producing, 

 by their united action, the effect, is what I call relation; 

 and wherever this is observed in the works of nature or of 

 man, it appears to me to carry along with it decisive evi- 

 dence of understanding, intention, art. In examining, for 

 instance, the several parts of a ivatch, the spring, the barrel, 

 the chain, the fusee, the balance, the wheels of various sizes, 

 forms, and positions, what is it which would take an observ- 

 er's attention as most plainly evincing a construction direct- 

 ed by thought, deliberation, and contrivance ? It is the 

 suitableness of these parts to one another : first, in the suc- 

 cession and order in which they act ; and, secondly, with a 

 view to the effect finally produced. Thus, referring the 

 spring to the wheels, our observer sees in it that which orig- 

 inates and upholds tlicir motion ; in the chain, that which 

 transmits the motion to the fusee ; in the fusee, that which 

 communicates it to the Mdieels ; in the conical figure of the 

 fusee, if he refer to the spring, he sees that which corrects 

 the inequality of its force. Referring the wheels to one an- 

 other, he notices, first, their teeth, which would have been 

 without use or meaning if there had been only one wheel, or 

 if the wheels had had no connection between themselves, or 

 common bearing upon some joint effect ; secondly, the cor- 

 respondency of their position, so that the teeth of one Vv^hee] 

 catch into the teeth of another ; thirdly, the proportion ob- 

 served in the number of teeth in each wheel, which deter- 

 mines the rate of going. Referring the balance to the rest 

 of the works, he saw, when he came to understand its action, 



