attached although the brightness of the image or of the drawing surface may 

 not require moderating. 



In order to enable the somewhat large exit pupil of the microscope obtained 

 with low magnifications being fully utilised, the usual ABBE cube with aperture 

 of 1 mm can, with the two large drawing apparatus, quickly and conveniently 

 be exchanged for another of 2 mm aperture. 



Glasses to correct defects of vision are, if required, supplied with our drawing 

 apparatus. 



No. 109. *Old form of Camera lucida. This drawing prism is only 

 supplied in the form shown in Fig. 33. The prism casing turns round a hori- 

 zontal axis and is also adjustable in elevation. It is attached to the tube by 

 means of a sprung collar and can easily be turned aside. 



75. 

 Fig. 38. Drawing Prism (Camera lucida) No. 109. ( 3 / 4 and 2 / 1 Full Size.) 



On the Drawing Apparatus for low magnifications (Stand Pll), No. 102 



can only the drawing prism No. 109 be used. For the arrangement of this ap- 

 paratus, which can be equipped at the same time with an image-erecting micro- 

 scope, see pp. 6769. 



The ABBE drawing cameras are constructed in three different forms: 



No. 110. *Small ABBE Drawing Apparatus. The prism casing and 



the mirror the latter supported by an extended arm about 105 mm (4 in.) long - 

 are connected with the clamping ring by hinges. The size of the mirror is 

 50 X 75 mm (2 X 3 in.). The clamping ring is attached to the draw-tube before 

 putting on the ocular. The upper parts -- prism casing and mirror can be 



Drawing Prism (Camera lucida), in case 

 Small ABBE Drawing Apparatus, in case . 



Marks 



81 

 30.- 



Codeword 



Patron 



Patronato 



Qatt 



