CONSTRUCTION OF THE MICROSCOPE. 



56. Baker's Student's Microscope. Most of the conditions above 

 specified as desirable, are well fulfilled in the instrument represented in 

 Fig. 40; which might easily be brought into entire conformity with them. 

 It is extremely light and handy; and is so well hung as to be very steady 

 in all positions. It is provided with a rotating glass stage; and this car- 

 ries a cylindrical fitting (not represented in the figure) for the usual 

 Accessories. 1 



FIG. 40. 



Baker's Student's Microscope. 



Collins's Student's Microscope. 



57. Collins's Student's Microscope. This instrument (Fig. 41) is con- 

 structed on a plan altogether different; the body having the diameter of 

 that of the larger Microscopes by the same maker (Fig. 49), so as to receive 

 their eye- pieces, and being capable of elongation by a draw-tube to the 

 full ordinary length. It is provided with a rack-movement acting on a 

 carriage attached along the length of the body (as in the Jackson model) ; 

 and the top of this carries the milled-head for the fine adjustment, which 

 acts upon a lever near the bottom of the carriage, so as to raise or lower 

 a focussing tube within the nozzle of the body. 



58. Pillischer's International Microscope. The Student who may be 

 willing to incur a slight additional expense, for the sake of obtaining a 

 substantial and well-constructed instrument, cannot do better (in the 

 Author's judgment) than possess himself of the International Micro- 

 scope of Mr. Pillischer (Fig. 42), in which the advantages of British and 

 Continental methods are ingeniously combined. The pillar, carrying a 



1 The price of this instrument, with one Eye-piece and two Objectives (1 inch 

 and l-4th inch), in Case, is 5 guineas; or, with rack movement for coarse adjust- 

 ment, 6 guineas, 



