324 The adaptation of the Aneroid for surveying in India. [No. 4. 



" Fig. 1 . represents the external appearance of the Aneroid Barome- 

 ter t Fig. 2. its internal arrangement, where the dial is supposed to be 

 removed and the index-hand retained ; and Fig. 3. a perspective view 

 of the same.* 



" In Fig. 2. a is the metallic chamber or vacuum-vase, which receives 



* We beg to acknowledge the kindness of Mr. Dent, in permitting casts to be 

 taken of Figs. 3, 4, and 5, — Aneroid Barometer. 



