( 722 ) 



Here S tü is tho specific gravity of water at 0°, ," the viscosity 

 coefficient. By equalising 1 and 3 we find: 



C== *._J_(£Y ( 4) 



cZ 

 and we should now have to eliminate — between (2) and (4). In order 



to perforin this elimination we simplify (2). We consider the form 



d 

 in (2) between the brackets [ ] and keep m mind that — is very 



small, that k l is very much greater than k, and that k a may be 

 neglected with respect to the firsl term (which amounts to neglecting 

 the conduction of heat through the ice). 

 We may then write: 





Tlien we have 



C — 

 If we put 



It \ £, 



d pJ* i , d/ A "i 

 + /*£ 



^i? 2 ir5/ " 



f— ^ = — 7.4 X 10- 9 , Sk= 0.9167, IT =79.2, 



6' becomes 



1 



C = 3.3 X 10- !1 X 



In (4) we substitute 



S w = l, &= 0.9167, ( i = 0.0181, 

 tlien 



C = 1.600 ( - ) (5) 



Equalising the two values of C we have : 



dy l &, 



1 =2.0 x lo- 11 



or 



R ) R* d k x 



f dy ( d\ L , k. 



