522 



SCIENCE. 



[N. S. Vol. XXV. No. 640 



Vice-president and Chairman of Section B — 

 Dayton 0. Miller. 



Retiring Tioe-president — W. 0. Sabine. 



Members of the Sectional Committee — W. 0. 

 Sabine, Dayton C. Miller, A. D. Cole, G. F. Hull, 

 F. E. Nipher, E. L. Nichols, A. Trowbridge, E. B. 

 Eosa. 



Secretary of Section B — ^A. D. Cole, Ohio State 

 University, Columbus, Ohio. 



On December 28, the retiring vice-presi- 

 dent, Professor Henry Crew, of North- 

 western University, gave a most interest- 

 ing and important address on 'Fact and 

 Theory in Spectroscopy'; this address was 

 printed in full in Science for January 4, 

 1907. 



Probably the sessions of Section B have 

 never before been attended by so large a 

 number of representative physicists; at 

 some of the meetings more than one hun- 

 dred and fifty persons were present. The 

 papers were many (nearly fifty in number) 

 and were, upon the whole, of a very high 

 order of merit. The meeting was uni- 

 versally pronounced a most successful one. 



There was no distinction between the 

 programs of the Physical Society and of 

 Section B; the abstracts and titles of the 

 papers of both societies are given below. 



Effect of a Magnetic Field upon the Ioniza- 

 tion in a Closed Vessel: W. W. Strong, 

 Johns Hopkins University. 

 According to present views, atoms eon- 

 tain charged particles which are in rota- 

 tion. In magnetic substances such as iron 

 or oxygen more of these charged par- 

 ticles rotate in one direction than in an- 

 other, and these orbits of rotation lie in 

 the same or in parallel planes. In a mag- 

 netic field atoms would turn so that their 

 planes would be perpendicular to the field. 

 The effect of the field would then be to 

 decrease the velocity of these charged par- 

 ticles, but not to change their radius of 

 rotation. This would make the atom more 

 stable. One could expect that the natural 



ionization in a closed vessel would be de- 

 creased by the application of a strong 

 magnetic field. This was the effect looked 

 for. 



The electroscope consisted of a sheet-iron 

 box of some three litres volume containing 

 air at atmospheric pressure. The charged 

 electrode consisted of a wire bent into the 

 arc of a circle at one end. The gold leaf 

 was attached to a rod at a point slightly 

 different from the center of the electrode 

 arc. The length of the gold leaf being 

 slightly less than the radius of this arc, at 

 different positions its end would be at dif- 

 ferent distances from the charged elec- 

 trode. By this means the gold leaf could 

 be made very sensitive to changes of volt- 

 age of the charged electrode. The gold 

 leaf was earthed. 



By using a large electromagnet the rate 

 of leak was found to be changed as much 

 as thirty parts in a hundred at times 

 although this change was not found to be 

 constant. The greatest effect was found 

 when the field was turned on for the first 

 time. An example of the readings are as 

 follows, they being made consecutively: 



Leak in Scale Divi- Rate of Leak 



3ion3 of Micrometer in Scale Divisions 



Time. Microscope. per Second 



Field on, 663 sees 737 .00111 



Field off, 613 sees 876 .00143 



Field on, 515 sees 540 .00105 



Field off, 520 sees 835 .00161 



The writer can not attribute this change 

 as due to any other effect than that of a 

 magnetic field on the natural ionization. 

 It may be possible, however, that there is 

 some other explanation. 



Projections of the Globe Appropriate for 

 Laboratory Methods of Studying the 

 General Circulation of the Atmosphere: 

 Cleveland Abbe, United States Weather 

 Bureau. 



The general circulation of the atmos- 

 phere is controlled by the general distribu- 



