588 Transactions of the Society. 



XIX. — Apparatus for Photomicrography with the Microscope 

 standing in any Position, especially in Inclined Position. 



By Domingo de Orueta, F.R.M.S. 



(Read April 19, 1911.) 



It will be agreed that the inclined position is the most comfortable 

 one, and that the advantage of working in this position increases 

 when large Microscopes are used. When, however, working with 

 the inclined Microscope, it is desired to photograph the object 

 under study, the position of the Microscope must be changed to 

 the horizontal or vertical, and sometimes the instrument must be 

 taken to the special table that holds the optic bench, with its 

 illuminating apparatus : once there it must be centred again, and 

 adapted to the photographic camera. All this is inconvenient and 

 takes some time. There is also the greater inconvenience, that 

 the good illumination obtained in direct observation is lost when 

 the position of the Microscope is altered, and all the preliminary 

 operations must be re-undertaken. 



The apparatus described in this note has been constructed to 

 avoid these inconveniences, and with the following aims. 1. To 

 enable photomicrographs to be taken with the Microscope in any 

 position, especially in the inclined one, without either moving the 

 instrument or modifying or changing the illumination. 2. To 

 secure that the apparatus shall always be ready for use, yet 

 without incommoding the operator when not needed. 3. That the 

 resulting photomicrographs may be of the most convenient size ; 

 that the camera may be lengthened or shortened in order to vary 

 the magnification ; and that the image may be focused on the 

 ground glass or transparent screen as easily as it can be done with 

 the ordinary horizontal camera. 



The camera when fully extended has an optical length of 

 0-8 m. (31^ in.), taking plates of 13 by 18 cm., or smaller sizes. 



A short explanation of the figures will be sufficient. 



The camera (constructed by the firm of Carl Zeiss, of Jena), is 

 mounted on a cylindrical bar B, along which either the front of 

 the focusing screen can be moved at will, and when adjusted, fixed 

 in any desired position by means of screws, the ends of which 

 enter a V-shaped groove running the whole length of the bar (so 

 that both front and back are always vertical). 



The bar B slides forwards and backwards in a collar C, and can 

 be fixed in the position desired. This enables the whole camera 



