4 NATURAL THEOLOGY. 



haps some previous knowledge of the subject, to 

 perceive and understand it ; but being once, as we 

 have said, observed and understood,) the inference, 

 we think, is inevitable, that the watch must have 

 had a maker: that there must have existed, at some 

 time, and at some place or other, an artificer or 

 artificers who formed it for the purpose which w^e 

 find it actually to answer ; who comprehended its 

 construction, and desis^ned its use. 



I. Nor would it, I apprehend, weaken the con- 

 clusion, that we had never seen a watch made ; 

 that w^e had never known an artist capable of 

 making one ; that we were altogether incapable of 

 executing such a piece of w^orkmanship ourselves, 

 or of understanding in what manner it was per- 

 formed ; all this being no more than what is true 

 of some exquisite remains of ancient art, of some 

 lost arts, and, to the generality of mankind, of the 

 more curious productions of modern manufacture. 

 Does one man in a million know how oval frames 

 are turned?* Ignorance of this kind exalts our 



+ It is certainly a thing not easily expressed in words. The 

 nave of a circular wheel moves on a single pivot ; but there are 

 here two pivots, and grooves in the wheel to correspond with 

 them. These two grooves cross each other, and play upon the 

 pivots in such a manner that the centre of motion varies, and the 

 rim of the wheel moves in an ellipsis. It is exactly on the same 

 principle that we draw an oval figure, by driving two nails into a 

 board, and throwing a band round them, and then running the 

 pencil round within the band. These two nails are in the points 

 called by mathematicians the foci of the oval or ellipse ; and ac- 

 cordingly, a fundamental property of the curve is, that the sum of 



