LXVIII ROYAL SOCIETY OF CANADA 
Sulphur Mountain, Banff, at an altitude of 7,484 feet; and this observatory 
begins to yield a harvest of facts concerning the movements of the 
upper strata of the atmosphere. The marked contrast in the character 
of the vertical temperature gradient, as indicated by observation at 
Sulphur Mountain and Calgary in warm seasons and cold seasons, is 
instructive, and cannot fail to be of value in the solution of problems 
connected with the physics of the atmosphere and in the study of the 
climate of our western plains. 
A further extension of the work of the Central Office is now proposed, 
and with this end in view the services of a highly trained physicist have 
been obtained, and investigation of atmospheric currents will shortly 
be made by kite and sounding balloon, and observations of atmospheric 
electricity. and conductivity and ionization will be carried on con- 
currently with the study of pressure changes. 
MAGNETIC OBSERVATIONS. 
The instruments at the Magnetic Observatory, Agincourt, have 
been kept in operation throughout the year. Weekly determinations 
of the absolute values of declination and dip and bi-monthly deter- 
minations of the horizontal force have been made, and, from the results 
obtained, the values of the photographic records of the variometers 
have been computed. 
During the month of October the observer in charge took simulta- 
neous observations of declination, inclination, and horizontal, force with 
an officer of the Dominion Astronomical Observatory; and during 
November observations were taken with two officers of the Department 
of the Interior in order to determine the constants of dip circle No. 77. 
The Surveyor General having inaugurated the taking of compass 
determinations of declination by certain surveyors, it became necessary 
to establish the index corrections of these instruments, and, in accordance 
with his instructions, sixty-two instruments have been sent at various 
times to this Observatory by surveyors engaged in the work. 
The index corrections to these instruments have been established 
by comparison with our Standard declinometer, two sets of observations 
being taken for each instrument. Duplicates of these observations 
have been sent to the officer of the Topographical Branch who has 
charge of this work, together with such comments as were deemed ne- 
cessary. It is very obvious that the observatory holds an important 
place as a base station for the science of Terrestrial Magnetism in. 
Canada, and also as a centre at which the standard instruments of other 
countries may be compared with those of the Dominion. Within the 
past year determination of the Magnetic values have here been made 
