THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FIFTH SERIES.] 



JUNE 1879. 



LXI. On the Thermal Conditions and on the Stratification of 

 the Antarctic Ice. By 0. Fisher, Clk., M.A., F.G.S.* 



SIR WYVILLE THOMSON delivered a lecture at Glas- 

 gow, November 23, 1876, " On the Condition of the 

 Antarctic"!. In it he gave a most interesting and graphic 

 account of observations made during the visit of the ' Chal- 

 lenger ' to high southern latitudes. Towards the conclusion 

 of the lecture, the author advanced some speculations about 

 the probable thickness and physical conditions of the antarctic 

 ice-cap. There appeared also in the 'Quarterly Journal of 

 Science ' for J anuary last an article from the pen of Dr. Croll, 

 which contained certain criticisms upon the conclusions arrived 

 at by Sir Wyville Thomson, and giving reasons why the ice-cap 

 may be considerably thicker than that philosopher supposes. 



I venture to think that there are a few points left in a some- 

 what uncertain state by both these gentlemen, which a little 

 mathematical treatment, of by no means an abstruse nature, 

 may assist in clearing up. 



The first of these relates to the limit of thickness which the 

 effects of temperature might impose on the antarctic ice. 



Dr. Croll remarks that there are but three sources from 

 which the ice-cap can receive an appreciable amount of heat, 

 viz. (1) the air above, (2) the earth beneath, (3) the work of 

 compression and friction. The last of these he dismisses as in- 

 considerable, and without doubt rightly so. 



* Communicated by the Author. 

 t 'Nature/ vol. xv. pp. 102, 120. 



Phil. Mag. S. 5. Vol. 7. No. 45. June 1879, 2G 



