PHYSICS — CARHART, FRANKI^IN, LE;WIS, NICHOLAS. 



227 



and its attached cylinders must be made, especially as regards any change 

 of period that may occur. Corrections for temperature have been applied, 

 but these should be checked. Then additional series will be made for a final 

 determination. 



In the table the word " chemical " refers to the check cell in which the 

 mercurous sulphate used was made by chemical precipitation ; " electro- 

 lytic" designates cells with electrolytically prepared mercurous sulphate. 



These values are for the temperature 20° C. 



This mean value for cells made with electrolytically prepared mercurous 

 sulphate is 6 parts in 100,000 lower than the one found by Guthe, as given 

 in his final report in the Bulletin of the Bureau of Standards, vol. 2, No. i. 



Franklin, "W. S*, and Freadenbergef, L. A*, South Bethlehem, Pennsylvania, 



and Newark, Delaware. Grant No. 344. A new method of measuring 



electrolytic resistances. $250, 



This grant was for the purpose of construction of apparatus during the 



summer of 1906. Dr. Freudenberger reports that this preliminary work has 



been done, showing that the alternating current galvanometer possesses 



excellent working characteristics for the purpose of measuring electrolytic 



resistances. 



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

 No, 150. Photographic investis^ations of vacuum-tube spectra of gases and 

 vapors. (For previous reports see Year Book No. 3, p. 128, and Year 

 Book No. 4, p. 253.) $500. 



The large quartz spectrograph provided for by this grant has been com- 

 pleted and adjusted for work, and a description of the instrument has been 

 published in the Astrophysical Journal for June, 1906. At present a series 

 of investigations on vacuum-tube spectra is being carried on with the partic- 

 ular object of ascertaining the relationship between the nature of the electric 

 discharge and the accompanying differences observed in spectra. It is hoped 

 that some results will shortly be ready for publication. 



