334 THE MICROSCOPES OF 1894. 



Leitz' Microscope. 



In the January number of this Journal (page io6) for last 

 year, we called attention to the fact that at last one of the con- 

 tinental makers had adopted the tripod form of foot. Conti- 

 nental microscopists have to thank Herr E. Leitz, of Wetzlar, 

 for this improvement in their instruments. By the courtesy of 

 Messrs. C. Baker, we are enabled to give an illustration (Fig. lo) 

 of the stand in question. The only feature that we need point 

 out in this instrument is the sub-stage, which has an excentric rack- 

 and-pinion movement, and can also be moved in or out of position 

 as required. A horse-shoe stage can be supplied instead of the 

 circular one as depicted. 



Watson & Son's "Grrand Model Van Heurck" Microscope. 



This instrument (Fig. ii), which we have reserved till last, as 

 all the preceding forms are of the student's or low-price class, fully 

 answers up to its title ; it is a superb microscope. The stand is 

 mounted on a massive tripod foot, which has a spread of lo inches 

 in each direction ; when in an horizontal position, the instrument 

 has a lo-inch optical centre. The coarse adjustment is by rack- 

 and-pinion. The fine adjustment is by a finely threaded screw, 

 which bears on the end of a powerful lever ; this adjustment was 

 first adopted by Zentmayer, of Philadelphia, but after a short time 

 was found to work unsteadily ; to Messrs. Watson belongs the 

 credit of rectifying the error in the design and in practically making 

 the adjustment their own : it is now one of the most exquisitely 

 delicate and reliable forms of fine adjustment. Rack-and-pinion 

 and sliding movements are also attached to the draw-tube. The 

 stage, which has rectangular rack-and-pinion movements, is pro- 

 vided with finders, and can be completely rotated when required. 

 The sub-stage has centring screws, a coarse adjustment by rack- 

 and-pinion, and a fine adjustment by micrometer screw. 



In microscopy it is often said that, given a good instrument, it 

 all depends on the man at the other end. We can now say, Here 

 is a good instrument ; now bring your man. 



