200 Mr. A. E. Dunstan on the Coefficient of 



Fur. 3. 



■35 



•25 



•05 











r 



i 











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f 













93 

 / 



/ 



1 











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V 



'St P 1 



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A 



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lb* 



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£50 



500 -750 



/<?/?£ /N GRAMS. 



1000 



1250 



I50O 



2. On plotting the corresponding coefficients of viscous 

 traction against the percentage composition of the alloys a 

 hyperbolic curve is obtained, which indicates that the relative 

 effect o£ tin on the mobility of lead is very great, whilst that 

 of lead on the mobility of tin is very small. The maximum 

 divergence from the normal did these alloys follow the mixture 

 law, is at 2 Pb 1 Sn. 



3. The coefficient of viscous traction is a function of the 

 load, and in some cases is very considerably affected by the 

 load used. This statement is, however, strictly applicable only 

 to those alloys containing less than 10 per cent, of tin. 



