78 
No. 
Marks 
Fig. 36. 
Abbe Camera lucida. 
44 The same Apparatus, with lar ger mirror on longer arm, 
so arranged that the prism case together with the 
mirror may be swung back round a horizontal pivot, the 
underpart remaining meanwhile on the tube in its adjusted 
position. (Fig. 35.) 
43. 
Fig. 36. 
Drawing Prism. 
45 
Drawing Prism (Camera lucida) with two prisms ; for fixing 
over the eye-piece. (Fig. 30.) 
31.- 
