An eye is for all the world exactly like a cannon, in this respect; That it is not so much the eye or the cannon, in themselves, as it is the carriage of the eye----and the carriage of the cannon, by which both the one and the other are enabled to do so much execution. 
An eye is exactly like a cannon, in this respect; that it is not so much the eye or the cannon, in themselves, as it is the carriage of the eye - and the carriage of the cannon, by which both are able to do execution. 