ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



651 



Simple Apparatus for Drawing and Photographing Microscopical 

 Sections.* — This apparatus, designed by J. Tandler, consists (1) of a 

 drawing-box carrying on its top a photographic bellows ; (2) of a box 

 enclosing the light source. The drawing-box is closed in front, open 

 behind, and has a trapezoidal-shaped base of dimensions : rear 65 cm., 

 front 35 cm., width 35 cm. The front wall is strong and 55 cm. high ; 

 the back wall (oblique) is not so high, and slopes roof -wise towards 

 the level top. The reason for this shape is that the observer, sitting at 

 the side of the box, may comfortably work with his right arm in the 

 box. In both the front and back walls there is a series of slides for 

 receiving the drawing board. A right-angled totally-reflecting prism 

 with the hypotenuse blackened, is placed over the upper end of the 

 bellows. Rays of light originating from the light-source then pass 

 horizontally through the Microscope, are 

 reflected at the prism, and pass vertically 

 downwards through the bellows on to the 

 drawing board in the box. The source of 

 light is generally an incandescent lamp. The 

 author keeps the arrangement installed in 

 the rear of his workroom, the front (closed) 

 side being towards the window. In this way 

 he finds that the image projected into the 

 box is bright enough without further darken- 

 ing of the room. By removing the prism, 

 and by setting the bellows horizontally on a 

 board with runners, the apparatus can be used 

 for photomicrography. 



J;z: 



..::>? 



(4) Photomicrography. 



J. W. Gordon's Apparatus for Photo- 

 micrography .f — In this application of photo- 

 graphy to the Microscope, the instrument is 

 used in a vertical position. The apparatus 

 consists of a tube A, about 6 in. long, which 

 is placed over the eye-piece. At the upper 

 end of this tube B, a photographic plate, 

 If in. square, is held by means of a cap C, in 

 a light-tight chamber ; between this and the 

 eye-piece is a projection lens focused upon 

 the plate, and a small exposing shutter D is 

 placed in the tube for making the exposure 

 (fig. 152). 



If the observer's eyesight be normal, the 

 photograph will be sharp when the Micro- 

 scope is in its ordinary focus, but, as almost everyone has slight errors 

 of vision, it has been found desirable to supply a duplicate tube E, 

 with a focusing eye-piece of high power, which is first placed on 

 the instrument in order to focus, and is then replaced by the camera. 



* ZeitBchr. wiss. Mikrosk., xxi. (1904) pp. 470-4 (3 figs.). 

 t R. and J. Beck's Special Catalogue, 1905, 4 figs. 



Fig. 152. 



