192 PRESIDENT S ADDRESS. 



to push the slide about on the fixed stage, much in the same 

 way as is done by the fingers. It must be remembered that 

 serial section cutting has made great strides during the past 

 few years, and as farther progress in this direction is to be 

 expected in the future, the advanced student's microscope must 

 be supplied with a good mechanical stage, giving a range of at 

 least 2 inches transverse, and 1^ inch of vertical movement, if 

 it is to keep pace with the times. Messrs. Zeiss have given atten- 

 tion to this subject and have fitted their large microscope with 

 a mechanical stage * possessing the above range of movement. 

 It has, however, that which seems an objection, viz., the 

 pinion for the transverse movement is placed nearly vertically 

 on the stage, somewhat after the method employed by Tolles,t 

 and which, it must be feared, proved a failure. The same firm 

 have also introduced an improved Mayall stage which is of 

 much practical merit. 



In substages we have a cheap centring one by Watson. X As 

 this can be fitted at small cost to the most elementary micro- 

 scope it will supply a much needed want. 



We have a new portable microscope by Swift on the lines of 

 their new four-legged microscope, exhibited last year,§ only 

 further portability is secured by folding up the stage and the 

 front legs. The one Messrs. Swift and Son have made for 

 me has my horse-shoe stage, no less than 5 inches wide by 4^ 

 deep, the body being capable of extension from 4J- to 12| 

 inches, yet this packs in a case only 6 inches wide, 5 \ deep, and 

 8 high. The weight of the instrument, with mechanical stage, 

 all brass, is 7Jlbs. 



A pretty little microscope, || VIa, of the Hartnack type, is 

 made by Messrs. Zeiss ; it is supplied with a chromatic con- 

 denser and iris diaphragm. This stand seems to be the limit to 

 which those built on the Hartnack plan should be carried. It- 

 is difficult to understand the advantage that arises from over- 

 loading a microscope built on defective lines with all kinds of 

 elaborate and expensive movements which can never yield the 



* Tom. cit., p. 99, 3 figs. 



f " Journ. B.M.S.," 1881, p. 117, 2 figs. 



X This Journal, 1895, p. 151, 1 fig. 



§ " Journ. R.M.S.," 1894, p. 506, fig. 33. 



|| "Journ. R.M.S.," 1895, p. 224, fig. 26. 



