ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



519 



Fig. 85* shows the same firm's new roof -prism (" Dachprisma "). It 

 is intended to serve the purpose of an erecting-lens in optical instru- 

 ments, accomplishing the same object without loss of light. The prisms 

 are totally reflecting, and hare no cement layer. 



<■- 



Fig. 85. 



Fig. 84. 



Simple Drawing and Projection Apparatus.! — TV. Imboden has 

 devised an apparatus for drawing microscopical low power objects. It 



Fig. 86. 



consists of : (1) a Microscope inclined to a horizontal position, fitted 

 with a long-focus condenser, a 1-in. objective and one or two oculars ; 

 (2) a projecting mirror ; (3) a light-screen ; and (4) an adequate 



* Catalogue, Astrononiische-Optik. 



t Journ. Quekett Micr. Club, x. (1909) pp. 353-6 (2 figs.). 



