308 



Mr. W. R. Browne. 



Description of glass yessel. 

 Bohemian tubing .... 

 ,, beaker. . . . 



Florence flask. . 

 French „ 

 Japanese globe, 

 Test-tube 



Resistance in ohms 

 per cub. centim. 



605 xlO 11 

 425 x 10 11 

 542 XlO 11 

 715 x 10 11 

 469 x 10 9 

 996 XlO 9 

 210 x 10i° 

 144 xlO 9 

 350 xlO 9 

 285 x 10 10 

 125 x 10 9 

 147 xlO 10 

 364 x10 s 

 155 xlO 9 

 374 xlO 9 

 196 x 10 9 

 933 xlO 9 



Density. 



9 



Li 



^OU 



O 



Li 



■497 



9 



Li 



•4^4 



O 

 Li 



Oc / 



o 



Li 



OLiO 



o 



Li 





9 



Li 



t/lU 



9 



Li 





o 



Li 





o 



Li 





9 



Li 





o 





2 



•53 



2 



•55 



2 



•57 



2 



667 



2 



•547 



The specimens marked (*) were of Japanese manufacture ; the first 

 four being potash lime glass, and the last soda lime glass. The other 

 test-tubes were supplied from England, and were probably German 

 white glass. 



The next table contains a similar comparison for a few specimens of 

 flint glass. The columns have the same meaning as in the last 

 table. 



Tumbler of toughened glass. 



622 x 10 10 



Piece of tubing 389 x 10 11 



Japanese globe 120 X 10 12 



Cylindrical cup with hemi- 

 spherical base of arsenic - 

 enamel glass 302 X 10 12 



A Thomson's quadrant electro- 

 meter jar 102 X 10 13 



2 -670 

 2 753 

 2-840 



3-070 

 3 172 



On the Causes of Glacier-Motion." By Walter R. Browne, 

 M. Inst. C.E., late Fellow Trin. Coll., Cambridge. Com- 

 municated by Professor Stokes, Sec. R.S. Received 

 June 1. Read June 15, 1882. 



The question of the causes which produce the movement of glaciers, 

 which was at one time so eagerly discussed, would appear to have 

 slumbered for the last ten years. This cannot be said to arise from 



