LX THE ROYAL SOCIETY OF CANADA 



information regarding the character of any large 'disturbance and the 

 distance from Toronto to the epicentre as ascertained from the time 

 of arrival of the various waves. The Toronto evening papers are 

 sometimes furnished with copies of the disturbances. 



I hope shortly to replace the present Milne instruments, which 

 are considered obsolete, with the new type as adopted by the British 

 Association at a large number of their stations; and also to equip 

 the Magnetic Observatory at Meanook, Alta., with a similar type of 

 instrument. The old Milne instruments fail in a great number of 

 cases to register the preliminary waves of distant quakes. The study 

 of these waves is of considerable importance at the present stage of 

 seismological investigation, as they afford the means for increasing 

 our knowledge of the structure and formation of the interior of the 

 earth, and it is desirable that they be distinctly recorded. The new 

 type of instrument fulfills these conditions. 



Agricultural Meteorology 



Statistical studies of wheat and oats in respect to the relation 

 between the yields and the weather-changes have been carried on 

 during the year. The Dominion Experimental Farms, through the 

 co-operation of Dr. Shutt, have aided as before by maintaining special 

 plots of wheat near the meteorological instruments. Upon these plots 

 the growth of the straw and the occurrence of certain vegetative epochs 

 have been noted for the years 1915, 1916, 1917 and 1918. A prelimin- 

 ary notice of the studies regarding wheat by Mr. A. J. Connor, based 

 on the results from the Experimental Farms and from the statistics of 

 Spring-wheat yields in Manitoba since 1890, was published by the 

 Department of Trade and Commerce in the Monthly Bulletin of 

 Agricultural Statistics for April, 1918. The correlations between the 

 yield and the temperature and rainfall of each 30-day period after 

 sowing were there tabulated. It was shown that the period from the 

 60th to the 90th day after sowing was the most important and that 

 during that period moist cool weather with a low daily range of temper- 

 ature is required for a large yield. Since the rainfall of the third 

 period is related positively to the yield, and the minimum temperature 

 and the range of temperature related negatively, the quotient 



7-: was plotted against the yields; and certain equa- 



range x minimum 



tiens which resulted, when finally solved, yielded the formula: 

 Y= -434 1 m--;- I log. ^ 



("0 



rm 



