LXXII THE ROYAL SOCIETY OF CANADA 



wheat in tlie Canadian West in relation to the seasonal changes in 

 the prevailing winds of the North Temperate Zone was devised 

 during the year and explained before the Toronto meeting of the 

 American Meteorological Association. The maps made in this con- 

 nection showed the futility of attempts at artificial rain-making and 

 also showed that for the southwestern districts of the wheat region 

 frequently recurring dry years are normal and that, therefore, irriga- 

 tion canals should always be kept in good repair from season to 

 season, even in years of ample rainfall. 



Having regard to the growing interest in Canada with respect 

 to problems of reforestation this Division has instituted a study of 

 variations in the growth of pine and spruce in order to trace the 

 effect of the weather changes and of local climates. At the present 

 time sections of aged felled trees, or even of stumps, are easily obtained 

 and the date of the last annual ring identified with certainty. A 

 collection of such sections from different parts of Canada is being 

 made and correlations of annual ring-growth with weather computed. 

 It is proposed to increase the collection by having paper-impressions 

 made wherever possible by Meteorological inspectors in future when 

 on annual inspections of out-lying stations. 



Magnetics.- — Photographic records of the variations taking place 

 in the Magnetic elements during the fiscal year 1921-22 were obtained 

 at Agincourt with only very slight loss. Pronounced disturbances 

 were of very infrequent occurrence as was expected in a year of 

 minimum sunspots. 



On the 12th of May, however, a very remarkable series of dis- 

 turbances began which lasted until the 21st, and were repeated at 

 each rotation of the sun for several months, although with much 

 diminished energy. During the May disturbance the limits of our 

 recording instruments were exceeded and for several hours the record 

 was lost. In Declination the range was greater than 4° and in Hori- 

 zontal Force nearly I2OO7, which is almost 8% of the normal value. 



Absolute observations for D, H and I were made each week 

 and base values for the differential instruments determined from 

 them. 



Tables showing the Magnetic character of each day of the year 

 were prepared and copies forwarded to the International Commission 

 on Terrestrial Magnetism. The "Selected days" of the commission 

 are used in the analysis of the Magnetic data for our Annual Magnetic 

 Report. 



At the request of the Surveyor General, index corrections for 

 compasses attached to Surveyors' theodolites to the number of sixty 



