BAKER'S BINOCULAR. 



89 



described. It is not fitted with sub-stage, but such an 

 appliance may be readily attached, dovetailed grooves being 

 left for the purpose. The motions to stage and body, and 

 general finish, are similar to those of the best instruments, 

 and it is altogether such a microscope as can be well re- 

 commended for medical or other purposes where a good 

 stand is required, and to which it is intended that further 

 additions shall be hereafter made. 



A smaller compound achromatic microscope, called the 

 " Educational," fig. 44, is made by Mr. Baker. This is 

 peculiarly adapted for students, and is supplied in a neat 

 mahogany case, with the necessary apparatus and excellent 

 object-glasses, for the small price of 41. 4s. If with iron 

 stand and in portable case, 31. 3s. 



Mr. Baker, in his binocular instrument, fig. 46, has 

 succeeded in reducing some of the difficulties to a mini- 

 mum. The setting of the prism, with its necessary stops, 

 is so contrived that it is contained 

 in one piece or fitting, so that 

 when the monocular body is re- 

 quired to be used, this piece can 

 be removed, and an uninterrupted 

 field obtained, the light enter- 

 ing the tube at the utmost obli- 

 quity for high powers. At fig. 45, 

 the body and nose-piece is seen de- 

 tached. It has this advantage, 

 that the prism remains in perma- 

 nent adjustment when the brass 

 nose-piece B is screwed home. 



Another feature in connexion 

 with the use of the binocular, 

 and not the least important, is 

 that of illumination ; we have 

 been much pleased with the sim- 



pie arrangement of a cheap con- 

 denser by the Same optician. It 



consist? of two plano-convex lenses, the lower one being 

 hemispherical ; the upper lens (of a Bomewhat smaller 

 diameter) is placed just within its focus ; the two are 

 fitted into a sliding-tube which admits of easy adjustment 



A. Bodies detached Jrom Stand. 

 * Hose-piece containing Pria*. 



