Mabch 19, 1909] 



SCIENCE 



471 



Most of the striking results of electro-culture, 

 including those recently obtained by Sir Oliver 

 Lodge, are quite readily accounted for, if the 

 above conclusions are correct. 



This paper was illustrated by means of several 

 photomicrographic and other lantern slides. 



Vote on the Kathode Equilibrium of the Weston 

 Cell: F. A. Wolff, Bureau of Standards, Wash- 

 ington. 



The Theory of Coupled Circuits: Lotus Cohen, 



Bureau of Standards, Washington. 



It is a well known phenomenon that when two 

 electrical circuits are coupled together either 

 electromagnetieally or direct, two distinct oscil- 

 lations will be produced in either circuit, and 

 there will also be two distinct damping factors. 

 The problem was the subject of several important 

 papers by several eminent German physicists, but 

 there are certain mathematical difficulties inher- 

 ent in the problem, which made it difficult to get 

 the complete solution, and all previous investiga- 

 tors limited themselves to some form of approxi- 

 mation. 



In. this paper an entirely different method of 

 mathematical treatment was adopted and which 

 made it possible to obtain an exact solution. The 

 paper being of a mathematical nature it is rather 

 iiifficult to give an outline of the work in an ab- 

 stract. The results are as follows: If we denote 

 by y, and Y^ the potentials in the primary and 

 secondary circuits, we have 



Fi = {flie-«i« -f flje-ai'} cos \t 



4- {Sje-"!' + fl^e-"!*} cos \t, 

 Fj = Jjie-"!' + e-02*} cos \t 



+ H^{e-nt -f- e-aji} cos 7~.jt, 



«! and 02 are the damping factors, Xi and Xj are 

 the frequency constants and they have been com- 

 pletely determined. 



Photographic Registration of Sounds: Dayton C. 

 MiLLEB, Case School of Applied Science, Cleve- 

 land. 



For making large scale records, showing the de- 

 tails accurately, of complex sound waves having 

 frequencies ranging from 500 to 10,000, the phono- 

 graph and oscillograph methods seem unsuitable. 

 The following direct mechanical method has given 

 satisfactory results. 



A small steel cylinder, 1 mm. in diameter, is 

 arranged to receive angular motion with a mini- 

 mum of reaction effects, which is proportional to 

 the displacement of a sensitive diaphragm. A 

 minute mirror, with its plane in the axis of the 



cylinder, reflects light to a special camera, and at 

 a distance of 30 cm. gives waves 15 cm. wide 

 which show great detail. Long strips of photo- 

 graphic films were shown and projected by the 

 lantern, showing with great clearness and in full 

 detail the record of overtones, intensity variation, 

 etc., of various spoken phrases. (The words 

 " physical laboratory " received careful and in- 

 terested attention from the audience.) 

 The Thermodynamics of Saturated Vapors: J. E. 

 SiEBEL, Chicago, 111. (Read by title.) 

 The object of this paper is to demonstrate the 

 necessity of an investigation as to whether cer- 

 tain hypothetical concepts in the theories of ther- 

 modynamics and which find their most general 

 expression in the assumption of a imiversal identi- 

 cal zero of energy ( — 273° Cels.) and a supposed 

 universally irretrievable dissipation of energy are 

 equally applicable to the thermodynamics of sat- 

 urated vapors as they appear to be to the thermo- 

 dynamics of permanent gases. 

 The Heat Balance in Thermoelectric Batteries: J. 

 E. SiEBEL, Chicago, 111. (Read by title.) 

 The author attempts to show that the heat and 

 electricity exchanged in thermoelectric elements 

 are functions of temperature, specific heat and 

 conductivity and produces a formula and calcu- 

 lations made thereby, the results of which latter 

 conform apparently well with a number of experi- 

 mental results obtained by other observers. 

 The Effect of the Magnetic Impurities in the Cop- 

 per Coils of Moving Coil Galvanometers upon 

 their Sensitiveness, Hysteresis and Zero Shift: 

 Anthony Zeleny, University of Minnesota. 

 The magnitude of the eflfect due to the magnetic 

 impurities in the copper coils upon the sensitive- 

 ness of a moving coil galvanometer was determined 

 by obtaining the period of vibration of the coil 

 system in and out of a magnetic field. 



If M represents the moment, per unit angle of 

 displacement of the coil, due to the magnetic im- 

 purities; T, the torsional moment; and ii and t, 

 the periods of vibration of the system when the 

 coil is within and outside of the magnetic field; 

 then 



M/T= (f — t^') /t^'. 



The value of the galvanometer constant is in- 

 creased due to the magnetic impurities by the 

 factor (1 + M/T). 



The values of M/T were determined for several 

 galvanometer coils in fields of various strengths 

 produced by an electromagnet. The values, when 

 using a 1.5 mil phosphor-bronze strip for the 

 upper suspension, varied for different coils from 



