THE COMPOUND MICROSCOPE. 



lO'i 



Fig. 53. 



down the tube into which it fits.* The centre of the stage is 

 made of black glass, ground very smooth, which looks neat, 

 and is not easily soiled or scratched. 



nachet's microscope. 

 The form of stand adopted by M. Nachet, to whom micro- 

 scopists are indebted for several ingenious pieces of apparatus 

 presently to be described, is, in many respects, similar to that 

 of Oberhauser, and is represented by fig. 54 ; the chief diflfe- 

 rence in the base of the stand being the length of the tube, F, 

 for the purpose of adapting the sliding frame, T, and lever, L. 

 The coarse adjustment is made by rack and pinion, by which 

 the tube, B, into which the compound body. A, shdes can be 

 moved up and down ; whilst the fine is effected by the screw, 



* M. Oberhauser, in his later instruments, has done away with the rack 

 movement, and has placed the milled head for the fine adjustment at the 

 bottom of the support of the compound body, instead of at the top. He 

 has also increased the length of the compound body. 



