40 



Besides the mechanical and revolving stages, auxiliary apparatus serving 

 the purpose of moving microscopical objects may also be employed. 



The Prism Rotator is a suitable accessory to the Binocular Stand X a and 

 also to other stands having a stage aperture of 33 mm (about 1 3 / a in.) diameter. 

 The Capillary Rotator may be used in connection with stands having a smaller 

 stage aperture. (For particulars regarding the above two appliances refer to 

 pp. 89 and 90.) 



For the purpose of determining the amount of very delicate movements 

 in o n e particular direction, especially where exact measurements of horizontal 

 displacements are in question, our Stage Screw-Micrometer (see p. 78) 

 will be found ' useful. 



We may here also mention the MALTWOOD Finder (see Zeitschrift f. 

 wiss. Mikrosk., vol. V, 1888, p. 40), which is an auxiliary appliance for reminding 

 any particular spot in a specimen under examination. It is a "finder" appliance 

 of the simplest description and may be used with any of our movable stages. 

 (See p. 93.) 



C. The Focussing of the Objectives. 



The coarse adjustment. The whole of the microscope stands specified 

 in this catalogue are provided with rack and pinion for the coarse adjustment. 

 We have constructed special machines for the accurate production of the oblique 

 toothgearing, and this motion is now made in such perfection that even objectives 

 of medium power can be focussed with sufficient exactness by it alone without 

 the use of the micrometer-screw. 



The fine adjustment. The micrometer movement introduced by us in 

 1886 (see Zeitschr. f. wiss. Mikroskopie, vol. Ill, 1886, pp. 207209) has during 

 this long period been in extensive use and has proved absolutely satisfactory. 

 We have therefore retained it in the Stands IV, V and VI. The superiority of 

 this is mainly due to the fact that the force exercised by the micrometer-screw 

 is transferred to the movable body by a single contact between two hardened 

 steel surfaces, which ensures an extremely delicate and uniform motion. 



In 1898 we introduced an entirely new type of construction of the 

 upper part of the Stand. The coarse adjustment by means of rack and pinion 

 was retained, hut the mechanism for fine adjustment underwent a complete 

 change. 



