TELEOLOG Y OF PALE Y, ETC. 13 



for a purpose, e. g. that they are so formed and adjusted 

 as to produce motion, and that motion so regulated as 

 to point out the hour of the day : that if the different 

 parts had been differently shaped from what they are, 

 of a different size from what they are, or placed after 

 any other manner, or in any other order, than that in 

 which they are placed, either no motion at all would 

 have been carried on in the machine, or none that 

 would have answered the use which is now served by it. 

 To reckon up a few of the plainest of these parts, and 

 of their offices all tending to one result : we see a cylin- 

 drical box containing a coiled elastic spring, which, by 

 its endeavours to relax itself, turns round the box. We 

 next observe a flexible chain (artificially wrought for 

 the sake of flexure) communicating the action of the 

 spring from the box to the fusee. We then find a series 

 of wheels the teeth of which catch in, and apply to each 

 other, conducting the motion from the fusee to the 

 balance, and from the balance to the pointer; and at 

 the same time by the size and shape of those wheels so 

 regulating the motion as to terminate in causing an 

 index, by an equable and measured progression, to pass 

 over a given space in a given time. We take notice 

 that the wheels are made of brass in order to keep them 

 from rust ; the springs of steel, no other metal being so 

 elastic ; that over the face of the watch there is placed 

 a glass, a material employed on no other part of the 

 work, but in the room of which if there had been any 

 other than a transparent substance, the hour could not 

 have been observed without opening the case. This 

 mechanism being observed, .... the inference, we 



