252 THE HISTORY AND DEVELOPMENT OF THE MICKOSCOPE 



i> fixed to tin- \\ooden l>;isis of the instrument, and places for the 

 lenso arc made in grooves beneath the hand-supports. The ad- 

 vantages of this general design have now been satisfactorily de- 

 mon.--! rated hv tlie large use that has been made of it; but the 

 details of its construction (such as the height and slope to be 



FIG, 203. Laboratory dissecting microscope (ISi"''. , 



to the hand-rests) may be easily adapted to individual require- 

 ments. 



A very simple and well-known form of dissecting microscope is 

 made by Messrs. Bausch and Lomb. It is shown in fig. 204. Its 

 form is self-explanatory : a plain glass stage, and a mirror at a suit- 

 able angle giving abundant light, capable of being replaced by 



KM,. 204. Bausch und Lomb's i "Burnt-si dissecting microscope (1896). 



a white or black enamelled background, suitable rests for the 



arm, and a sliding holder for the lenses. It is these latter that 



special lliey are designed for the instrument. They are 



which undoubtedly gi\e a large aplanatic field and fine 



definil ion. 



the \t-ry Le*1 form of dissecting microscope for simple lenses 



