650 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



have, says Prof. Eobin, " a character of precision and finish quite remark- 

 able." 



Fig. 169 



Fia. 170. 



Prism for Drawing. — In accordance with our custom of chronicling 

 microscopic apparatus actually brought to the condition of practical manu- 

 facture and use, we note this device of an anonymous 

 designer. 



It consists of a right-angled prism, not attached 

 above the eye-piece, but placed at the nose-piece over 

 the objective, the image being reflected on paper placed 

 on the table on which the Microscope stands. It 

 cannot, however, be used with ordinary Microscopes 

 where the body-tube is in front of the limb, but only 

 with such forms as the Watson-Moss,* where the 

 body-tube is at the side. 



Bausch and Lomb Optical Go's. Mechanical Stages. — These are made in 

 the two forms shown in figs. 171 and 172. Fig. 171 is 4^ in. in diameter, 



Fig. 171. 



and is intended to be used with the "Concentric" and "Professional" 

 Microscopes. It is thin, to allow great obliquity, but firm. The movements 

 are contained within the circumference of the stage, so that it can make 



* See this Journal, 1881, p. 516. 



