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 further additions may bo 

 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 Ail. 45. If with iron 

 stand and in portable case, 2>l. S*-. 



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

 succeeded in reducing some of the difficulties ta a mini- 

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

 is so contrived that they are con- 

 tained in one piece or fitting, so 

 that when the monocular body is 

 required to be used, and this piece 

 is removed, an uninterrupted field 

 is obtained, and light enters the 

 tu-be at the utmost obliquity for 

 high powers. At fig. 45, is seen 

 body and nose-piece detached. It 

 has this advantage that the prism 

 remains in permanent 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- a. Bodies detached Jrom stand. 



denser by the same optician. It ^- ^°'^-'JP^'<^^ containing Prism. 

 consists of two plano-convex lenses, the lower one being 

 hemispherical ; the upper lens (of a somewhat smaller 

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

 fitted into a sliding-tube which admits of easy adjustment. 



Baker's arrangement of 

 Wenham's Binoaidar. 



