The microscope is called by some a " machine ", 

 but we earnestly protest against this harsh term being 

 applied to an instrument of such precision. 



As it is necessary for the student to become 

 conversant with the names of the various parts and 

 to understand their use, we give an illustration, Fig. 25, 

 with the parts lettered for better identification, and 

 append a list giving their names. We recommend 

 that they be impressed upon the memory, as they 

 are the basis of microscopical language. 



A. Base, the foundation of the instrument. It 

 usually rests upon three points (or should do so) and 

 is of such weight that it keeps the instrument firm 

 when it is in an upright or inclined position. The 

 two principal forms are the horseshoe and tripod. 



B. Pillar, the vertical column which is fastened 

 to the base and carries in its upper end the joint or 

 axis which is provided for inclining the instrument. 

 It generally consists of one piece, either round or 

 square, but, in larger instruments, is often made in two 

 columns. 



C. Arm, supports all the upper working parts of 

 the instrument and carries the adjustments for focus. 



D. Body, the tube portion to which the optical 

 parts are attached. 



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