Mr. Wake gave the background to a recently published paper, Calorimetry of Oxidation, of which he was co-author.

The paper stemmed from the application of "high powered mathematics" to a chemical problem—that of finding the highest temperature in a body which is decaying or fermenting. This problem is relevant to spontaneous combustion in wool, hay or sawdust.

The problem was formulated mathematically in terms of differential equations and Mr. Wake described how he grappled with these to produce a result which satisfied the chemists.

The talk kept incomprehensible mathematics to a minimum and gave the audience a good insight into the development of applied mathematics in practice.

Account Of Aurora

Mr. Wright gave an account of the aurora and of the basic processes involved. Briefly, he said that protons and electrons from the sun or the Van Allen belts enter the earth's atmosphere and transfer some of their energey to oxygen atoms. The atoms so excited lose this extra energy by emitting light of a specific colour—red or green for oxygen.

By mathematical interpretation of a few carefully selected experiments, Mr. Wright was able to build up our present picture of the phenomenon. As yet there is no complete picture but through this study valuable knowledge about the upper atmosphere has been gained which could lead to improved radio communications.