1032 



SUMMAUY OF CURUENT RESEARCHES RELATING TO 



Microscope, The most convenient arrangement for the cord is shown 

 in fig. 178, in which position it can be used with a vertical, inclined, or 

 horizontal camera. 



Stenglein's Coarse and Fine Focusing Arrangements* — After de- 

 scribing a form of horizontal camera which docs not present any novel 

 features, Herr M. Stenglcin describes the method he adopts for moving 

 the coarse-adjustment. C (fig. 179) is the milled head of the Microscope 



Fig. 179. 



Fig. 180. 



round which is a cord ; C^ C^ are holes in the base-board for the cord to 



pass through, and C" C^ weights attached to the cord at the focusing end 

 of the camera. Each half of the cord passes over a couple of fixed 

 pulleys. 



The device employed for moving the fine-adjustment is shown in fig. 



180, and is claimed to be better than 

 any arrangement with toothed wheels. 

 It consists of a brass ring, the circum- 

 ference of which is a little larger than 

 the head of the micrometer screw ; on 

 its inner side are two fixed points, 

 while a third is supplied by a screw 

 which serves to secure the ring to the 

 milled head. To the outside of the 

 ring is fixed a light and thin brass 

 plate 45 mm. long, from the extremity 

 of which the cords pass over two pulleys 

 fixed to the board on each side of the camera. At the opposite end of 

 the camera the cords again pass over a pair of pulleys, and are kept 

 taut by a weight of 25-30 gr. By pulling one or other of the cords 

 motion is imparted to the micrometer screw. 



Adaptation of the ordinary Eye-piece for Photomicrography.! — Dr. 

 R. Neuhauss has found that if the lenses in the eye-piece be separated for 

 a little distance and an additional diaphragm fitted on, an image just as 

 sharp as can be obtained with the expensive projection-ocular is thrown 

 on the focusing screen. 



The arrangement is extremely simple ; a paper case or tube, 2^ cm. 

 long, is fitted on to the brass tube of the eye-piece. The internal 

 diaphragm remains in its original place, while the new one is fixed over 

 the eye-piece by means of a short movable tube. 



• Centralbl. f. Baktpriol. u. Parasitenk., iii. (1888) pp. 442-5, 471-5 (3 figs.), 

 t Zeitschr. f. Wiss. Mikr., v. (1888) pp. 328-9., 



