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exceedingly difficult matter to make an accurate adjustment in 

 this way, especially as the draw tube had to be considered. 



The President said they would be glad to hear Mr. Nelson's 

 opinion upon this eyepiece, and he could quite understand the 

 difficulty of using it as a correction, seeing how difficult it seemed 

 to some people to properly use the ordinary correction collar. 



Mr. E. M. Nelson said they had three microscopes sent for 

 exhibition by Messrs. Baker : the first was Eeichert's " Austrian " 

 model, fitted with an entirely new fine adjustment, in which 

 there were two levers bearing upon each other, interposed 

 between the micrometer screw and the top of the pillar. The 

 microscope itself was essentially the old form, but with an 

 invention applied to it by which the fine adjustment was 

 immensely improved, so that whereas in the old form the speed 

 was at the rate of ^J' for each turn, it was in the new form 

 only o-^o'. Another good feature was that the indicator for 

 the divisions on the milled head was adjustable so that it could 

 be put at zero at any time, enabling the reading to be obtained 

 direct instead of having to reckon it ; the coarse adjustment was 

 also adjustable so that they could get either a loose or a tight 

 rack. The first Continental microscope with a sprung rack was 

 made by Leitz, but this one of Reichert's was made on a different 

 principle. The instrument had a 1|" substage and a horseshoe 

 foot. The second microscope was practically the same, only 

 more elaborately and expensively fitted. The third was a new 

 and cheap form containing a condenser formed of a loup in the 

 manner he had himself suggested some time ago. It was not 

 usual to mention prices, but he thought under some circumstances 

 it was permissible to do so, and although very well made they 

 would perhaps be astonished to find that this microscope was 

 sold for £2. The tendency now seemed to be towards making 

 thoroughly good working instruments at low prices. 



Mr. Nelson also exhibited one of Messrs. Watson's Edinburgh 

 Students' Microscopes fitted with his stage and his latest improved 

 coarse adjustment — viz., a stepped rack formed of two plain racks 

 with a single pinion. In the ordinary rack-and-pinion movement 

 there was always a slight loss of time between the change of 

 direction of the movement, but in the case of the stepped rack 

 one worked on the upward and one on the downward movement, 

 the result being that the pinion acted at once, and there was 



