204 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



of each tube, the tubes being set at an angle to each other for this 

 purpose. Each tube carries both an objective and ocular. The two 

 objectives are mounted on a single slide, the lenses being carefully paired, 

 and provision is made by a suitable adjusting arrangement to enable 

 one to focus the object for each eye separately. Correction is thus 

 made for any slight difference that may exist in the eyes of the observer. 

 Provision is also made for adjusting the oculars to the correct width 

 between the pupils of the observer's eyes. The stand comprises a heavy 

 horse-shoe base, of generous dimensions, carrying a substantial pillar, to 

 which the stage and body are fitted. The latter is considerably over- 



Pig. 21. 



hung, and is secured by an approved hinged joint which permits the tilt- 

 ing of the instrument through an angle of 90°. By an extremely simple 

 slide joint, locked by a single milled-head screw, the upper portion of the 

 instrument may be detached and reversed (fig. 21). An examination is 

 thereby possible of bulky specimens of too great a weight for the stage, 

 or of such size that the Microscope must be mounted above or placed 

 upon them. Independent rack-and-pinion movements are provided to 

 the Microscope and the stage. These adjustments, together with the 

 slide and clamp of the body of the Microscope, permit of the examina- 

 tion of specimens of considerable variation in length. The stage is 

 modelled upon the English pattern, and is strongly constructed. It is 

 provided with anterior, posterior, and lateral movements of considerable 

 range. The surface-plate upon the stage is removable, and covers an 

 opening. The instrument is thus available for such other purposes as 



