Manchester Memoirs, Vol. xlii. ( 1 898), No. 0. 1 5 



water, which was the temperature of the laboratory, so that 

 there would be no cause of conduction unless the tempera- 

 ture of the shaft bearing was raised by friction. When 

 the lubrication was good this was small, although on one 

 or two occasions it made itself felt. 



The idea of raising the temperature from 32° to 212°. 



These tests became an annual, and very instructive 

 exercise. But as the value of the equivalent was then a 

 subject of much discussion, the desire to obtain measures 

 of it from these trials by those engaged in them, resulted 

 in Mr. T. E. Stanton, M.Sc, then senior demonstrator in 

 the laboratory, effecting, for his own satisfaction, a com- 

 parison of the scales of the thermom.eters used in these 

 experiments with a thermometer used in the physical 

 laboratory, which had been corrected by the air ther- 

 mometer, and introducing the corrections into the results 

 of these trials, which so gave values very close to what 

 might be expected. 



The author could not, however, see that determinations 

 based on such corrections could have any intrinsic value, 

 but as the matter was exciting great interest in the 

 laboratory, he carefully considered the conditions which 

 would be necessary to render the great facilities which the 

 brake was then seen to afford, available for an independent 

 determination. 



The institution of an air thermometer was considered 

 and rejected, but it occurred to the author that it might 

 be possible to avoid the introduction of the scales of 

 thermometers just as before, and yet obtain the result. 

 If it could be arranged that the water should enter the 

 brake at the temperature of melting ice, and leave it at 

 the temperature of water boiling under the standard 

 pressure, all that would be required of the thermometers 

 would be the identification of these temperatures. 



