v> 



SECOND-CLASS MICROSCOPES. 



and thumb to the projecting pin, the bar with the attached eye- 

 piece be raised or lowered, the other eye-piece also is moved 

 accordingly. The Stage is provided with a brass Object-carrier, 

 which is fitted to it in the same manner as the glass object-carrier 



Fig. 38. 



Crouch's Student's Binocular. 



of MM. Nachet's Microscope (Fig. 37), and works with the like 

 freedom and smoothness ; but it does not possess that immunity 

 to injury from acids or saline fluids which is so valuable a feature 

 in MM. Nachet's construction. This, however, may be obtained, 

 in combination with the rotatory movement which the Author 



