PHYSICS. 357 



The primarj'' object of the determination of evaporation by this investiga- 

 tion was to furnish a safe basis for certain investigations of stream-flow. 

 During the past year, when fairly good values for the evaporation constants 

 had become available, the direct investigation of stream-flow was commenced 

 and is now being carried forward at the same time that the evaporation 

 investigation is being completed. As was expected, this has already thrown 

 valuable sidelights on the evaporation investigation and has thus promptly 

 justified the overlapping of the two related investigations of evaporation 

 and of stream-flow. 



On September 5, 1923, four least-square solutions, each dealing with the 

 observed discharge for one or two months on one or the other of two small 

 streams in Colorado, have been completed. These solutions indicate that the 

 theory on which this investigation is based is sound and that the method of 

 investigation is capable of furnishing rapid progress in determining the laws 

 connecting stream-flow on the one hand with the observed meteorological 

 elements in the drainage area of the stream on the other hand. 



Millikan, R. A., Norman Bridge Laboratory of Physics, Pasadena, California. 

 Research associate in physics. 



Under the 1922-23 grant of $15,000 by the Carnegie Corporation of New 

 York for work on atomic structure to be carried on in the Norman Bridge 

 Laboratory of Physics, the 35 subjoined distinct researches have been carried 

 on by 31 different men, all of whom have received assistance in greater or less 

 amount from this fund. The results obtained so far have been reported in 17 

 different papers read before the American Physical Society. A few of these 

 researches which have yielded results of somewhat more than the usual 

 interest are selected for brief description. 



1. The magnetic investigations conducted by S. R. Williams, in addition 

 to bringing to light some interesting relations between the changes in the 

 dimensions of iron and steel bars and their magnetization, have incidentally 

 jaelded a new magnetometer which may revolutionize the making of magnetic 

 surveys. It is a simple, rugged, and easily portable instrument, capable of 

 giving a determination, accurate to 1 part in 1,000, of the horizontal or 

 vertical components of the earth's magnetic field in a few minutes of time and 

 also of exploring quickly and accurately the magnetic fields of solenoids, 

 electromagnets, etc. 



2. The work of Messrs. Millikan and Eyring in pulling electrons from cold 

 metallic surfaces by static fields has shown : 



(a) These currents set in from untreated tungsten at a field-strength of 

 about 200,000 volts per centimeter and rise a billionfold, nearly reversibly, 

 as the field increases to 1,000,000 volts per centimeter. 



(6) This phenomenon of the pulling out of electrons is entirely independent 

 of temperature. 



(c) It is a phenomenon which is dependent upon the electron aflfinity of the 

 very surface molecules, an electro-positive molecule on the surface acting 

 apparently as a hole through which the reservoir of electrons inside may be 

 tapped so as to produce a well-nigh unlimited flow. 



These results are of both scientific and industrial interest. 



3. The experiments of Otis, Bowen, and Millikan have established the 

 existence of a very penetrating radiation in the upper regions of the 



