THE MICROSCOPE. 



ICKOSCOPE, the name of an in- 

 strument for enabling the eye to 

 see distinctly objects which are 

 placed at a very short distance 

 from it, or to see magnified images 

 of small objects, and therefore to 

 see smaller objects than would 

 otherwise be visible. The name 

 is derived from the two Greek 

 words, expressing this property, 

 MIKBOS, small, and SKOPEO, to see. 



So little is known of the early 

 history of the microscope, and so 

 certain is it that the magnifying 

 power of lenses must have been 

 discovered as soon as lenses were made, that there is no reason 

 for hazarding any doubtful speculations on the question of 

 discovery. We shall proceed therefore at once to describe the 

 simplest forms of microscopes, to explain their later and more 

 important improvements, and finally to exhibit the instrument 

 in its present perfect state. 



In doing this we shall assume that the reader is familiar with 

 the information contained in the articles " Light/' "Lens," 

 "Achromatic," "Aberration," and the other sub-divisions of 

 the science of Optics, which are treated of in this work. 



The use of the term magnifying has led many into a miscon- 

 ception of the nature of the effect produced by convex lenses. 

 It is not always understood that the so-called magnifying power 

 of a lens applied to the eye, as in a microscope, is derived from 



