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A.—MATHEMATICS AND PHYSICS. 29 
the mechanism of tropical cyclones is the same or whether we have here 
something more of the nature of the process described by Sir Oliver Lodge, 
meteorologists are not yet agreed. We need more observations, especially 
of the conditions in the upper air over tropical cyclones, before this question 
can be decided. At present we must leave it an open question. 
These new ideas have had a far-reaching effect on the practical applica- 
tions of meteorology, especially in the domain of weather forecasting. 
The old method of weather forecasting was mainly empirical and based 
on the work of Abercrombie. Abercrombie had sketched the distribution 
of weather about centres of high and low pressures, and forecasting was 
based on the determination of the movement of these pressure distribu- 
tions when they appeared on the weather chart, the assumption being 
made that as the pressure system passed over a place the normal sequence 
of weather would be experienced. 
Now the forecaster has much more knowledge of what I may call the 
anatomy of a depression. The pressure distribution is, of course, still the 
main factor, but the forecaster searches his chart for indications of the 
surfaces of discontinuity, and examines the characteristics of the air 
masses to see whether they are of polar or equatorial origin. In this way 
he is able to determine the structure of the cyclone and whether it is 
developing or dying. Having determined where the surfaces of dis- 
continuity are situated, he is able to say where rain may be expected, and 
he knows what weather changes will accompany the passage of each surface 
of discontinuity as it moves over the surface of the land. He is aided in 
this by observations taken in the upper atmosphere by means of pilot 
balloons and aeroplanes fitted out with meteorological instruments. 
This has all resulted in greater confidence in the forecasts made, a 
confidence which is frequently justified by remarkably accurate forecasts. 
Unfortunately, however, the processes which take place in the atmosphere 
are extremely complicated, and perfect forecasts are still far from being 
attained. The progress made, however, is very encouraging, and, what is 
still more important, the paths along which further investigation must be 
made are clearly defined. Many more observations of the upper air are 
_ necessary, many more theoretical investigations have to be made in the 
- quiet of the study, and there is room for many more experiments in the 
laboratory. 
The problems awaiting solution are many and difficult and call for 
the highest skill in physics and mathematics. Why is it that these problems 
are entirely neglected in our great schools of physics and mathematics ¢ 
The official meteorologist is struggling to the best of his ability, but the 
number of meteorologists allowed to the Meteorological Office is governed 
by the practical application of the work. The official meteorologist has 
a full day’s work with his official duties and finds little opportunity to 
embark on theoretical investigations. We need the help of the universities, 
and the problems we offer, although difficult, are fascinating. Shall 
I appeal in vain for the study of meteorology to be taken up at our 
universities and colleges, where there are so many men and women with 
the knowledge and ability required for the work ¢ 
