NATURAL THEOLOGY. *S 



^differently shaped from what they are, of a differ- 

 ent 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 which would have answered the use that is 

 now served by it. To reckon up a few of the plain- 

 est of these parts, and of their offices, all tending 

 to one result: — We see a cylindrical box contain- 

 ing a coiled elastic spring, which, by its endeavour 

 to relax itself, turns round the box. We next ob- 

 serve 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 that 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 w^atch there 

 is placed a glass, a material employed in 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 be seen without opening the 

 case. This mechanism being observed, (it requires 

 indeed an examination of the instrument, and per- 



