144 THE ROYAL SOCIETY OF CANADA 



4. On a New Lecture Room Illustration of Atomic Models 



By Louis \'. King, D.Sc, F.R.S.C. 



The essential feature of this form of atomic model is the use of a 

 powerful alternating field, in which steel spheres or needles repel one 

 another with forces which are remarkably uniform. Attraction to 

 some fixed centre can easily be arranged for in a number of ways. 

 Under this system of forces the spheres or needles arrange them- 

 selves in concentric rings, resembling some of the atomic models 

 which ha^■e been proposed. 



The Transmission of Heat Through Thin Boundary Films of Air or of 

 Water at the Surface of Glass. 



By A. Norman Shaw, D.Sc, and L. A. Smith, B.A. 



Presented by A. S. Eve, F.R.S.C. 



The following points were discussed in the paper: 



1. The immediate need and the practical application for further 

 physical data of this type. 



2. The experimental determhiation of normal surface con- 

 ductivities. 



3. The results obtained by the writers for the equivalent thermal 

 conductivities of thin films of water or of air at the surface of glass. 



4. Comparisons of the thermal conductivities and also of the 

 temperature gradients for the different parts of a double window. 



5. Observations on single-frame double windows. 



^X.B. — -As part of this work has been reported in the Journal of the American 

 Society of Heating and Ventilating Engineers for December, 1920, and as a full 

 account is to be published later, this paper was not submitted Jor further publication 

 here. 



