24 



OPTICAL PRINCIPLES OF THE MICROSCOPE. 



a manner, that the image may be formed of dimensions not too 

 great for the whole of it to come within the range of the Eye- 

 glass ; and as it thus allows more of the object to be seen at once, 

 it is called the Field-glass. It is now usually considered, however, 



Fig. 13. Fig. 14. 



Diagram of simplest form of 

 Compound Microscope. 



Diagram of complete 

 Compound Microscope. 



