26 



Dr. W* S. Bay on a Comparison of 



S « 





a c3 



£ 



drawn in the neighbourhood of the points. The ordinates 

 deduced from this smooth curve give the corrected value of 

 the mechanical equivalent in kilogramme-metres at Baltimore, 

 as deduced from the comparisons described here. These 

 values are given in Table IX. in kilogramme-metres, and also 

 in the C.G.S. system. They are also shown in the curves 

 On this diagram are drawn curves representing 



in fig. A 



Ffc. 4. 



Ergs. 

















V loo « to* 



\ 



\\ 















tM<io«/o* 





\\ 













11 io « to* 





N 













V'-JO */0* 







~x 









-■ 



10° 15° 20° 25° 30° 



Temperature on the Paris hydrogen scale. 



35° 40 c 



Rowland's uncorrected values, the corrected values as given 

 in Table IX., and the values obtained by E. H. Griffiths, after 

 correcting them to the hydrogen scale (Phil. Trans. 186 a, 

 p. 361, 1893 ; Phil. Mag. xl. pp. 437, 147, 1895). Griffiths' 

 values were corrected to the hydrogen scale from the nitrogen 

 scale by means of the differences between the two scales as 

 given by the experiments of Chappuis (Guillaume, Thermo- 

 metrie de Precision, p. 258). Schuster and Gannon's value, 

 4*1917 x 10 7 at 19°*1, is also marked on the same diagram for 

 comparison (Phil. Trans. 186 A, p. 458, 1895). 



9. Schuster's indirect Comparison of Baudin 6166 

 with the Paris Nitrogen Thermometer. 



Before the comparisons described here were made, one of 

 Rowland's thermometers had already been compared indirectly 

 with the Paris nitrogen thermometer. In the summer of 



