ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



481 



in the general design of the Microscope, besides a few advantages which 

 have been secured. The arching of the Hmb affords not only a convenient 

 handle, whereby the stand may be grasped, but provides also an increased 

 working space on the stage. The stands of this type, thanks to the 

 precision of the new micrometer movement, have within a short time 

 secured such a large measure of popularity as to create the impression 

 that they are gradually supplanting Microscopes of the older type. It 

 would seem that the creation of these new models, by associating the 

 mechanical and optical qualities of German Microscopes with the elegant 

 design ' of the English models, signalises a new era in the construction 

 of Microscopes. 



Leitz Large Mechanical Stage.* — This apparatus (fig. 76), adapted 

 for the Leitz stands A, B, C, D, has very extensive lateral and vertical 

 movements, which are effected by rack-and-pinion. 



A^^imfet^htfaiS^^^Eit 



Fig. 76. 



Ettles-Curties Ophthalmometer and Ophthalmic Microscope. — 

 This instrument (fig. 77) is provided with a telescope having two 

 objectives well corrected for chromatic and spherical aberrations, and of 

 unusually large working aperture : between these two objectives a 

 Wollaston double-image prism is placed. 



The eye-piece is of the Ramsden type, and has a spider web fixed in 

 a set plane. The operator focuses this web and then knows that the 



* E. Leitz' Catalogue, No. 41, English edition, 1905, p. 89. 



