

5 II 



SUMMARY OF CUKKENT UKSKA IM'H KS RELATING TO 



another, one of which Berves for lateral displacement and the other for 

 focusing the image on the screen. The former movement is especially 

 useful when taking stereoscopic pictures, and both are provided with 

 lengthening rods, so that the adjustments are easily effected when the 

 operator is sitting in front of the focusing plate. For the vertical ad- 

 justment of the object a rack-and-pinion adjustment is provided, upon 

 which is mounted a universal arm carrying a glass rod, the possible 

 movements of which are well shown in the illustration, the object being 

 fixed to the point of the rod by an adhesive, or by first mounting upon 

 cork. 



In order to render the apparatus suitable for taking pictures by trans- 

 mitted light, the universal arm figured and described must be removed 



Fig. 65. 



from the pillar actuated by the rack-and-pinion and replaced by a vertical 

 stage. The illuminant (Liliput arc or incandescent gas) and condenser 

 are then mounted on a special removable optical bench behind the stage. 

 Leitz' microsummars will be found particularly useful with this appa- 

 ratus ; but, if higher magnifications, such as can only be obtained with a 

 compound Microscope, be required, a tube carrying objective and eye- 

 piece can he screwed into the front of the shutter, thus dispensing with 

 I he ordinary Microscope stand. 



Barnard's Practical Photomicrography.*— In this work the subject 

 is treated by the author, J. E. Barnard, in a simple and straightforward 

 manner, and from first-hand knowledge. He remarks in the preface 

 thai it is one thing to he conversant with the practical side of the subject. 



'• London : Edwin Arnold (1911) xii. and 322 pp. (10 pis. and 79 figs.). 



