734 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



Apparatus for Drawing Objects Natural Size. * — Mr. H. Bausch 

 describes an apparatus (figs. 205, 206) for drawing objects. The optical 

 parts are attached to a horizontal arm supported by a cylinder which 

 sheaths and is freely movable up and down upon an upright post, and 

 which is fixable by a side-screw. The eye-piece consists of a combination 

 of right prisms, and is attached to the horizontal arm opposite the sup- 

 porting post. Rectangular mirrors, rigidly fixed to each end of the bar, 



Fig. 205. 



Fig. 206. 



E 



! 



are inclined at an angle of 45° to the horizontal. The optical parts of 

 the eye-piece consist of a cube formed by cementing two right prisms 

 together, the facing surfaces, with the exception of a very small area in 

 the centre, being silvered, thus forming a diagonal mirror through the 

 cube, the mirror being pierced at its centre by a small hole. To the 

 lower side of the cube is cemented a third right prism with its diagonal 



* Journ. Applied Microscopy, iii. (1900) pp. 891-3 (2 figs.). 



