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Mathematical and Physical Society

This year has been a record one in respect of the attendance at the meetings of the Society. The good start made in the first term has been followed by sustained interest during the second term, when a high average attendance was maintained.

A change in the committee occurred when Miss M. Downes left Wellington for New Plymouth. The service which Miss Downes has rendered to the Society is a matter of several years' standing, and has had a marked effect in its recent progress. Miss J. Comrie was elected to fill the vacancy.

Mr. F. F. Miles, M.A., gave an address on "Relativity." He pointed out how the ideas of Newton implied a narrow concept of the principle of relativity, and then proceeded to deal with the special theory and the general theory of relativity recently developed by Einstein and others. The relation and the transitions between the different systems were dealt with, and the position well illustrated by showing how Maxwell's equations for the propagation of an electromagnetic wave held for all systems, whereas Newton's formulation of the law of gravity would not bear translation into terms of the relativity theory.

A paper entitled "The Temperature Spectrum," was given by Mr. F. G. Caughley, in which he traced the series of effects on matter when it is subjected to successive regions of the electro-magnetic spectrum.

Mr. N. F. C. Hill delighted his audience with the explanation and demonstration of phenomena associated with "Liquid Air." The members utilised time usually given to discussion in repeating such experiments as the burning of carbon in liquid air, the freezing of carbon di-oxide in burning coal gas, and the splintering of frozen grapes and rubber.

Mr. M. F. Doig gave a paper on "Di-electric Losses and Cable Construction." The lecturer succeeded in making this rather technical subject interesting, and illustrated his matter with various lantern slides.

Mr. F. Jackson brought the Society into touch with engineering problems by giving an address on "Concrete and Bitumen," with special reference to road construction. This lecture provided relief from the academic nature of many of the papers and was illustrated by a splendid series of lantern slides.

"Equilibrium by Gyroscopic Forces," was the subject dealt with by Mr. G. J. S. Read. The action of working models of gyroscopes was examined and the principles involved were applied to the movements of the planets. The application of the theory to mono-rail vehicles was mentioned with reference to slides and models.

On behalf of Mr. G. D. Pollock, who was unavoidably absent, Professor Sommerville delivered a paper on "Railway Transition Curves." The difficulty of getting a train comfortably round a bend was explained, and the manner in page 12 which difficulties were overcome by mathematics, was clearly explained. Mr. Pollock had prepared interesting graphs and diagrams, and these well illustrated his subject.

The final lecture for the session, 1928, was given by Mr. J. W. Harding on "X-Rays and Crystal Structure." Mr. Harding went well into the subject of how the arrangement of molecules and atoms in a crystal could be studied by using the crystal as a diffraction grating of three dimensions for X-Rays. The technical methods for special conditions were explained, and the whole lecture illustrated by numerous carefully prepared diagrams.

The thanks of the Society are due and gladly extended to Mrs. Sommerville and Mrs. Florence, who have kindly provided supper at the meetings.