[stupart] PRESIDENTIAL ADDRESS 7 



fluctuation is associated with the sunspot numbers. This connec- 

 tion is brought out by taking the mean monthly values of the solar 

 constant measurenents at Mount Wilson from the year 1906 on, 

 and comparing them with the mean monthly sunspot numbers of 

 Wolfer for the same period. From such a comparison it appears 

 that the greater number of sun-spots the higher will be the solar 

 constant of radiation, and that an increase of a hundred sun-spot 

 numbers corresponds to an increase of about 0.07 calories per square 

 centimeter per minute in the solar radiation outside the earth's 

 atmosphere." 



We then have a varying solar radiation and this must to some 

 extent affect the temperature conditions of the earth. 



It is a warrantable inference that the equatorial region where 

 the rays strike most directly will répond most quickly to radiation 

 changes. 



It will be of interest to you to learn that in the very near future 

 all the British Meteorological Charts will be published in absolute 

 units. The pressure in millibars and the temperature in centigrade 

 degrees above absolute zero. The northern hemisphere charts pub- 

 lished in both England and the United States are already in this 

 system, and just as soon as the reports from Europe are telegraphed 

 to Canada in absolute units, just so soon will our working map be 

 prepared in those units as I am sure we shall find not the slightest 

 inconvenience in their use for the preparation of forecasts. 



