466 



SCIENCE 



[N. S. Vol. XLII. No. 1083 



proper motion at right angles to the direction of 

 the sun's way, also by a comparison of the paral- 

 lactic motion with the solar velocity. While the 

 results of these two methods differ considerably 

 their mean agrees with the observed parallax. 



On the Electrical Conductivity of Air Confined in 

 an Ice Vessel: Peofessoe J. C. McLennan, 

 F.E.S.C, and Me. Haeold G. Mueeay. 



On the Besidual Ionization in Gases over the Sea 

 and on the Surface of LaJce Ontario : Peofessor 

 J. C. McLennan, F.E.S.C, and Mr. C. L. Tre- 



LEAVEN, B.A. 



On the Absorption Spectra of Zinc and other Me- 

 tallic Vapors: Professor J. C. McLennan, 

 F.E.S.C, and Mr. Evan Edwaeds, B.Sc. 



Note on the Ultra-Violet Spark Spectrum of Sili- 

 con: Professor J. C. McLennan, F.E.S.C, and 

 Mr. Evan Edwards, B.Sc. 



On the Ionization Potentials of Mercury Zinc and 

 Cadmium Vapors and their Single Line Spectra: 

 Professor J. C. McLennan, F.E.S.C, and Mr. 

 J. P. Henderson, B.A. 



Application of Wilson's Method to a Study of the 

 Ionization Paths of Alpha Bays in Sydrogen: 

 Peofessoe J. C McLennan, F.E.S.C, and Mr. 

 H. N. Mercer, B.Sc. 



On the Delta Badiation from Zinc freed from Gases 

 under Bombardment by Alpha Bays: Professor 

 J. C McLennan, F.E.S.C, and Mr. C G. 

 Found, B.A. 



On the Infra-red Spectrum of the Mercury Arc: 

 Professor J. C McLennan, F.E.S.C, and Mr. 

 E. C. Dearle, B.A. 



On the Besolution of Spectral Lines by an Electric 

 Field: Professor J. C McLennan, F.E.S.C, 

 and Mr. K. H. Kingdon, B.A. 



On the Study of Bontgen Bay Spectra: Professor 

 J. C. McLennan, F.E.S.C, and Mr. A. E. Mc- 

 Leod, M.A., and Mr. E. L. Lewis, B.Sc. 



The Crushing Strength of Ice: Peofessoe H. T. 



Baenes, F.E.S.C, and Me. H. M. Mackay. 



Experiments on large blocks of ice were made 

 on the Emery testing machine. The results agree 

 with those presented last year. 



The Effect of Strain on the Thermal Expansion 



of Quartz: Peofessoe H. T. Barnes, F.E.S.C. 



Quartz rods were put under tension up to their 

 breaking point and the coefficient of expansion 

 measured between 0° and 100° C No effect was 

 observed. 

 Secondary Cathode Bays from Gases: A. Norman 



Shaw, D.Sc. Presented by Peofessoe H. T. 



Barnes, F.E.S.C 



On Osmosis in Soils: C J. Lynde, and V. V. 



DuPEfi. Presented by Peofessoe H. T. Baenes, 



F.E.S.C 



This paper gives the results of experiments made 

 to determine whether or not the pressures observed 

 are due to osmosis. 



On the Flow of Air m Two-dimensional Channels 

 with Special Beference to the Stability of 

 Stream Line Motion: Louis Vessot King, M.A. 

 (Cantab.). 



An account is given of experiments carried out 

 with the author 's hot-wire anemometer on the dis- 

 tribution of velocity in the flow of air between 

 parallel planes. The observations were taken with 

 a view of obtaining some light on the conditions 

 which determine the breakdown of stream-line mo- 

 tion into turbulent flow. 



On the Distribution of Air Velocity in the Neigh- 

 borhood of a Botating Cylinder: A. Geay, B.Sc, 

 and Louis Vessot King, M.A. (Cantab.). 



On the Calculation of the Self and Mutual Induc- 

 tion of Coaxial Cylindrical Coils: Louis Vessot 

 King, M.A. (Cantab.). 



I. A new method of deriving the formulae for 

 the self and mutual induction of coaxial cylindrical 

 coils is obtained by reducing the problem to one 

 of calculating a simple case of gravitational at- 

 traction. 



II. By the application of Gauss's theorem of 

 the Arithmetico-Geometrieal mean, the calculation 

 of the elliptic integrals which occur in the formula 

 for self and mutual induction of coaxial single 

 layer coils is made possible to a high degree of 

 accuracy with comparatively little labor of com- 

 putation and without the use of Legendre's tables. 



III. Simple quadrature and graphical methods 

 for the approximate calculation of the constants 

 are also described. 



Geometrical Configurations that lead to the Solu- 

 tion of a System of Partial Differential Equa- 

 tions of the Second Order: Chas. T. Sullivan. 

 Presented by Dr. J. Harkness, F.E.S.C. 

 Progress on the 12-inch Beflecting Telescope: Dr. 

 J. S. Plaskett, F.E.S.C 



The present condition of the grinding and pol- 

 ishing of the mirror and of the construction of the 

 mounting will be described and illustrated by lan- 

 tern slides. 



Liquid Chlorine as a Solvent: Cryoscopio Measure- 

 ments at Low Temperatures: P. Waentig and 

 D. MclNTOSH, F.E.S.C 



