216 Proceedings at the Meetings 



2. Preliminary note on antennal variation in an aphis {Myzus ribis, 

 Linn.). By Miss Maud D. Haviland. (Communicated by Mr H. H. 

 Brindley.) 



3. Studies on Cellulose Acetate. By Dr Fenton and A. J. Berry, 

 M.A., Downing College. 



4. The rotation of a non-spinning gyrostat, and its effect on the 

 aeroplane compass. By G. T. Bennett, M.A., Emmanuel College. 



5. Lagrangian methods for high-speed motion. By C. Gr. Darwin, 

 M.A., Christ's College. 



6. The effect of a magnetic field on the intensity of spectrum lines. 

 By H. P. Waran. (Communicated by Professor Sir Ernest Rutherford.) 



7. Generation of sets of four tetrahedra mutually inscribed and 

 circumscribed. By C. V. Hanumanta and Professor H. F. Baker. 



8. On the term by term integration of an infinite series over an 

 infinite range and the inversion of the order of integration in repeated 

 infinite integrals. By S. Pollard, M.A., Trinity College. (Communi- 

 cated by Professor G. H. Hardy.) 



9. On rotating liquid cylinders. By S. R. U. Savoor, B.A., Trinity 

 College. 



May 3, 1920. 

 In the Cavendish Laboratory. 

 Professor Sir Ernest Rutherford, Vice-President, in the Chair. 

 The following were elected Fellows of the Society : 



N. K. Adam, M.A., Trinity College. 

 P. A. Buxton, M.A., Trinity College. 

 N. M. Shah, B.A., Trinity College. 

 F. P. White, M.A., St John's College. 



The following was elected an Associate : 



K. W. Braid, Fitzwilliam Hall. 



The following Communications were made to the Society : 



1. Notes on the Theory of Vibrations. By W. J. Harrison, M.A., 

 Clare College. 



2. On cylical octosection. By W. Burnside, M.A., Pembroke 



College. 



3. (1) A bifilar method of measuring the rigidity of wires. 



(2) An experiment on a piece of common string. 



(3) Experiments with a plane diffraction grating, using conver- 



gent light. 

 By Dr G. F. C. Searle, Peterhouse. 



