( 721 ) 



The quantity C is not expressed here in C.Gr.S. units, since the 

 dimensions have been taken in millimetres, the velocities in milli- 

 metres per minute and (lie forces in grammes. In order to reduce 

 them toC.G.S. units, the value of C has to be multiplied by 170 ;< L0~ 9 . 



The values given in the table are averages of several measurements. 

 In order to show the deviations of different measurements, made with 

 the same weight, 1 give here an arbitrarily chosen set of separate 

 measurements. 



German silver wire, diameter 0.4 mm. 

 Number of the 



The value of C is calculated by Mr. Ornstein in formula (I) of 

 his paper. He finds 



'dt 



^dp 





wt R* WS; 



(2) 



Here k x , k. 2 and k s are the coefficients of heat conductivity respec- 



fd,t \ 

 tively of the wire, of water and the ice, ( — 1 is the rise of the 



melting temperature by pressure, measured at the melting tempera- 

 ture, W is the latent heat of melting ice, Si the specific gravity of 

 ice, R the radius of the wire and (/ the thickness of the layer of 

 water. Now the value of C cannot be calculated by this formula, 

 since the quantity d is unknown. But besides the equation (1) 

 Mr. Ornstein gives in his formula (IT) an expression, found by a 

 hydrodynamical reasoning, in which the quantity d likewise occurs. 

 This relation is v ) : 



- f - (3) 



Si 12 n [id l sin a \R 



S 

 l ) In Mr. Ornstein's paper this formula is given without the factor ,"' since 



this latter has no perceptible influence. 



