RUMFORD FUND. 371 



1920. 222. Frederick A. Saunders. Spectral lines. (Addi- 

 tional to 177.) $150 



223. David L. Webster. X-ray spectra. (Additional 



to 199.) ^. 350 



224. In aid of publication of Marie's Annual Interna- 



tional Tables of Constants, through Julius 

 Stieglitz. (Additional to 215.) 250 



225. Leonard R. IngersoU. Polarizing effect of dif- 



fraction gratings 150 



226. Harrison JNI. Randall. Structure of spectra, in 



infra-red. (Additional to 213.) 500 



227. Arthur G. Webster. Pyrodynamics and interior 



ballistics. (Additional to 216.) 500 



228. Norton A. Kent. Spectral lines. (Additional to 



197.) . 200 



229. William W. Campbell. For the purchase of a 



special photographic lens. (Additional to 139.) 360 



230. Horace L. Howes. Researches in luminescence. 



(Additional to 218.) 90 



231. Percy W. Bridgman. Thermal and optical proper- 



ties of bodies under high pressures. (Additional 



to 217.) 400 



