[shaver] 



ABSORPTION SPECTRUM OF OXYGEN 



in diameter, made of clear fused quartz which easily transmitted 

 radiation down to the wave length X = 2150 Â.U. This flask was 

 mounted in front of the slit of the spectrograph and filled with liquid 

 oxygen. As before, the light from the spark between aluminium 

 terminals under water was used as the source of radiation and some 

 well-defined broad absorption bands were obtained in the region 

 bordering that of complete absorption. These broad bands were 

 about 30 Â.U. in width, and within each one a fine set of symmetrical 

 triplet bands could be distinguished. The reproductionof the photo- 

 graph taken, which is given in Plate I , Fig. 3 (b) , shows the broad absorp- 

 tions but the sets of triplet bands are not so evident. However, it was 

 found possible to measure the wave lengths of the component bands 

 in three of these sets, and these results, together with the wave- 

 lengths of the broad bands, are given in Table II. The first column 

 contains the limits of the broad bands, the second their mean wave- 

 lengths, and the last gives the mean wave-lengths of the three sets 

 of fine bands. 



III. Absorption Spectrum of Gaseous Oxygen 



The absorption chamber for this experiment consisted of a brass 

 tube 35 cm. long and 2.5 cm. in diameter, threaded at each end so 

 that the brass holders which supported the windows could be securely 

 screwed on, making gas-tight joints. The windows were made of 



