222 



DR. W. GEOFFEEY DUFFIELD ON THE 



atmospheres, and by HUMPHREYS* at pressures of 42, 69, and 101 atmospheres. The 

 results of these two researches are given in full in the following tables. 



The displacements per atmosphere have been calculated from their measurements 

 and are set out in subsequent columns. The mean displacements per atmosphere have 

 been inserted, and may be compared with the similar values obtained in the present 

 research. 



The agreement is reasonable considering that in the previous investigations the 

 means for a large proportion of the lines are not based upon a very large number of 

 observations. The lines 172, 176, 178, &c., are, however, assigned larger displacements 

 by the writer than by HUMPHREYS. 



TABLE VI. 



* HUMPHREYS, ' Astrophysical Journal,' vol. XXVI., p. 36, 1907. 



