7 o 



LABOR A TORY MICROSCOPES 



[CH. II 





Fig. 69. The removable mechanical stage of the Spencer Lens Co. It is a 

 modification of a form devised by Winkel. Besides the general features mentioned 

 in ',. 121 it has the advantage of fitting any square stage. It is fastened to the stage 

 by the clamps shown at the right. Another form is made having one screw on 

 the side. 



