LXVI THE ROYAL SOCIETY OF CANADA 
A redetermination of the constants of the magnetometer used for 
absolute horizontal force measurements was completed in March 1911. 
These values have been used from the beginning of the year 1911. The 
results are 28y lower than formerly obtained with this instrument. 
The constants of magnetometer 146 of the Hydrographic Survey De- 
partment were determined in November and December and were found to 
agree with the constants furnished by Kew. Its correction to Toronto 
Standard was then determined and found to be -0.00109 part of H. 
During the year 90 theodolites with magnets attached were com- 
pared with the Agincourt Standard Declinometer and index correc- 
tions for the magnets were determined and supplied to the Surveyor 
General. 
Assistance was given to Mr. C. A. French of the Dominion Ob- 
servatory, in comparing his instruments with Agincourt Standards, 
both before and after his field work. 
An officer of the Meteorological Service, Mr. W. E. W. Jackson, 
M.A., was assigned to the Hydrographic Surveys Branch for the sum- 
mer of 1911, to carry on a Magnetic Survey of Hudson’s Bay and Strait. 
Owing to the unfortunate occurrence of a leak in the vessel, the survey 
had to be abandoned. 
The following results were, however, obtained : 




Declination cor- 
Date rected to mean Inclination H. F. 
STATION Lat. N.|Long.W.| 1911 of day C. G. 8. Minto 
Forteau. .....|51° 27’| 56° 55’| July 21 —31° 45’-7 
Green Cove. . .{57° 42’ | 61° 42’| Aug. 15 —42° 10’-2 80° 27’-0 0-09820 
Halifax.......|44° 36’| 63° 34’| Sep. 15 | —21° 35’-4 73° 49’-8 0-16149 
Rimouski. .. . .|48° 30’| 68° 31’| Sep. 18 | —22° 51’-4 76° 49’-1 0-13864 


The Milne seismographs at Toronto and Victoria have given con- 
tinuous records throughout the year, the former registering 85 dis- 
turbances and the latter 73. 
The more important shakes were two of Mexican origin on June 
7th and December 16th; two of West Indian origin—on October 6th, 
and 10th; an Alaskan quake on January 31st and one on March 11th, 
probably of submarine origin west of Vancouver Island, and which 
caused a sharp and large movement of the Victoria recorder and a 
lesser movement of that in Toronto. 
