Displacement of Spectral Lines. 



501 





Displacements in 



o 

 thousandths of an Angstrom 



Unic at 





15 at 



ns. 



30 atms. 



50 atms. 





Wave-length. 



in 





in 



in 





Air. 



OO r 



Air. 



C0 2 . 



Air. 



C0 2 . 





4422-67 



40 



39 R 



69 



67 



89 



97 





27-44 



68 



65 



142 



108 



190 



196 





42-46 



90 



91 



138 



105 



195 



200 





43-30 



62 



73 



108 



90 



100 



124 





47-85 



67 



80 



145 



120 



193 



173 





54-50 



46 



56 



86 



77 



108 



113 





59-24 



61 



68 



147 



126 



245 



240 





61-75 



40 



53 R 



69 



78 



103 



169 





66-70 



40 



45 R 



84 



64 



108 



104 





76-20 



41 



38 



79 



76 



116 



112 





82-35 



66 



70 



120 



119 



225 



237 





94-67 



82 



63 



147 



146 



250 



250 





4528-78 



(71) E 



72 R 



(170) 



142 



260 



255 





31-25 



45 



47 



88 



86 



126 



118 





47-95 



45 



39 



90 



83 



124 



148 





92-75 



50 



39 



84 



94 



130 



142 





4603-03 



44 



39 



94 



89 



117 



133 





47 54 



52 



40 



96 



83 



no 



114 





54-70 



25 



22 



58 



44 



85 



81 





91-52 



6S 



66 



104 



94 



129 



137 





4707-45 



191 



180 



315 



310 



(538) 



(520) 





10-37 



68 



69 



104 



112 



127 



129 





36-91 



179 



189 R 



319 



302 



(570) 



(544) 





Mean 



67 5 



67-1 



124-2 



113-7 



184-3 



188-6 









Mean displacement 

 per atmosphere. 



} « 



4-5 



4-1 



3-8 



37 



38 





of spectral lines. This is also in accordance with experiments 

 made by using pure metals and alloys of those metals or 

 carbon poles with metallic impurities, when the same pressure 

 displacements were practically found in each case*. All 

 these facts seem to show that the pressure displacement is 

 not a density effect, but is due to the total pressure of the 

 radiating vapour, i. e. to the compactness in number of 

 the atoms, irrespective of their kind. 



In conclusion L wish to thank Professor Rutherford and 

 Professor Schuster for the interest they have taken in this 

 research. 



Physical Laboratories, 

 Manchester University. 



* Humphreys, Astrophysical Journal, vol. xxvi. p. 18. Duffield, Phil. 

 Trans. Roy. So& A. vol. ccix. p. 218. 



