BAIRD &TATLOCK (LONDON) LTD, 



'] hf division of the pencil of rays emerging from the objective, with the object of producing two separate 



: ritocted at the upper end of the tube by partial reflection in a thin stratum of air between the two prisms 



1 lie bisection ot the pencils for producing stereoscopic effect is made by adjustable semicircular stops 



over the oculars ; without these, i.e., with fully exposed oculars, the instrument gives binocular vision witli- 



ne.cilic stereoscopic effect. 



The distance between the oculars is adjustable by altering the position of one of the ocular tulws to suit 

 he interpupillary distance of any individual observer's eyes. The instrument is available (but in conjunction 

 .vith achromatic objectives only) for use on any of our large stands in which the tubes admit of shortening to at 

 i-asi i-)o millimetres (5 \ in.). 



1126 



1127 



Zeiss' Large Mechanical Stage. 



The range of the movements of this pattern of stage is 50 millimetres (2 in.) in one direction and 3-, milli- 

 metres (i; in.) in the other ; the readings of variations in either direction are taken from scales and verniers. 

 <Sr<- /-ilsckr. f. wiss Mikrosk., vol. xi., 1894, pp. 301-304.) In the latest models a third scale and vernier is added 

 for recording the positions of the movable stop which secures the object slide. This arrangement facilitates the 

 convenient use of the apparatus a?, a " finder." and the process of centring is at the same time much simplified by 

 the addition of a centring-glass, an object slide having a cross ruled upon it. (For particulars see the directions 

 for using this apparatus.) 



1126 Large Mechanical Stage for Zeiss' Stands I., III., IV. 



Centring appliance, if not already supplied with the stand 



extra 



500 

 17 



1127- Attachable Mechanical Stage (old model) 

 1128 r Case for above . 



extra 



450 

 050 



