128 CARNEGIE INSTITUTION OF WASHINGTON. 



house. After consultation with Dr. Thompson, who had made im- 

 portant preliminary experiments with fused quartz at lyynn, Pro- 

 fessor Ritchey was fortunate enough to .secure the assistance of 

 Mr. Acheson, of the Acheson Graphite Company, and Mr. Tone, 

 of the Carborundum Company, at Niagara Falls, in designing a 

 special electric furnace for fusing the quartz. This is now under 

 construction at Pasadena. A 50-kilowatt transformer, giving from 

 15 to 30 volts, has been completed, and an optical pyrometer for the 

 measurement of the temperature of the fused quartz has been kindly 

 loaned by Dr. S. W. Stratton, Director of the Bureau of Standards. 



E. Percival Lewis, University of California, Berkeley, Cal. Grant 

 No. 150. To investigate vacmini-tube spectra of gases and vapors. 



$500. 



Abstract of Report. — This grant is to be expended mainly for quartz 

 lenses and prisms for a large spectrograph, designed for a more 

 systematic and detailed study of vacuum-tube spectra than has 

 hitherto been made. A part of the necessary materials has been 

 received, and it is expected that the .spectrograph will be completed 

 and in use in about two months. Meanwhile preliminary investiga- 

 tions have been carried on with a small spectrograph, the results of 

 which are described in two papers published in the Astrophysical 

 Journal for July, 1904. 



A. A. Michelson, University of Chicago, Chicago, 111. Grant No. 



47. For aid in riding diffraction gratings. $1 ,500. 



Abstract of Second Report. — Professor Michelson continued his ex- 

 periments during the year in connection with the building of ruling 

 engines for diffraction gratings. He found many difficulties, and has 

 not yet fully overcome all of them. The method employed for 

 ruling is based essentially upon the construction of a precision .screw. 

 Professor Michelson believes that he can obtain results of greater 

 value than have hitherto been reached by the development of a special 

 engine that he is now working upon. 



R. VV, Wood, Johns Hopkins University, Baltimore, Md. Grant 

 No. 120 For research, chiefly on the theory of light. (For first 

 report see Year Book No. 2, p. xxxix.) $500. 



Ayiovialons Dispersio7i of Sodijim Vapor. — A very complete study 

 has been made of the anomalous dispersion of the vapor of metallic 



