NATURAL THEOLOGY. 131 



B. I know not what contrivance could be more 

 plain, nor how any one can look upon it, without be- 

 ing persuaded of a desiging intelligence. 



T. We have another example of the same kind 

 in the trochlear muscle of the eye, from a Latin 

 word signifying a pulley. 



A. This muscle arises from the bottom of the 

 orbit or socket, and then comes forward and passes 

 through a loop on the inner edge of the socket, in 

 advance of the level of the eye, whence it returns 

 and is fastened to the ball : of course, when the 

 muscle contracts it rolls the eye. It operates ex- 

 actly in the same manner as a rope in a ship is car- 

 ried over a block or round a stay, in order to make it 

 pull in the direction which is wanted ; or, as in raising 

 one end of a stone pillar, the rope is passed forward 

 of the object, and then is reverted through a ring or 

 pulley as at a, in the following figure, and attached 

 to the weight to be drawn up. 



Fig. 23. 



