1)R W. GEOFFREY DUFFIELD ON THE 



Diagram 1 suggested that some relation of this sort might hold for the gold lines, 

 since several of these are in alphabetical order in the diagram. To investigate this 

 the rates of displacement of the lines were calculated by dividing the measured 



DIAGRAM 1 . 

 Pressure- Displacement Diagram 



So 100 150" 



Pressures in Atmospheres. 



200 



displacement by the number of atmospheres in absolute measure, and these are given 

 in Table V. on p. 65. 



In Diagram 2 the mean displacements that have been calculated for lines which 



4,200 4,400 , 



Wave-lengths. 



4,800 



5,ooo 



