50 EYE. 



beyond our ingenuity, it is probable ; and that is, as 

 the difficulty is owing to the form of the glass not 

 being so powerful in the middle, to increase the power 

 by making the middle of a more powerful kind of 

 glass, that is, of a more dense or solid kind. Wonderful 

 as it may seem, this contrivance is actually adopted in 

 the eye. The chrystaline, or principal glass of the 

 eye, is of greater solidity toward the middle. The 

 solidity increases from the edge to the centre. For 

 the glasses in a telescope to possess the same advan- 

 tage, it would be necessary they should each be made 

 of innumerable kinds of glass, gradually increasing in 

 solidity, from the edge to the middle of the glass. 

 This can hardly be done ; and hence the eye exhibits 

 an example of telescopical knowledge and ingenuity 

 which stands unrivalled. 



B. This is all new information. If one could not 

 understand a word, it would be delightful to hear of 

 all this curious philosophy in our eyes ; because it 

 seems a signal illustration of divine wisdom and in- 

 telligence. 



T. Are there any other respects in which this 

 wonderful organ displays the same sort of superiority ? 



A. Yes, there is one no less remarkable. The 

 light which comes from an object into a spying-glass 

 or telescope, and by which the object is seen, does 

 not all reach the eye. A part of it is thrown back 

 from every glass in the instrument; and this is no 

 benefit but a disadvantage. But there is no remedy. 

 It is a settled principle with respect to light, that 

 when it passes from the air into a telescope, some of 



