| Description | Results of the Makerstoun observations regarding the relation of the variations of the earths magnetism to the solar and lunar periods, by John Allan Broun, communicated by Sir Thomas [Makdougall] Brisbane. Results discussed are from 1844 to 1845 taken by the bifilar magnetometer.
Discussion on the diurnal variation of the horizontal force in 1844, and the mean diurnal range. Reference to Broun’s remarks to the physical section of the British Association. In June 1845 regarding the horizontal force and corrections to the Toronto observations. Discussion on the mean horizontal force for each month, the secular variation, the lunar period for the horizontal force, and Broun’s deductions based on the moons phase and synodical revolution.
Includes a method for rendering magnetical instruments self-registering by Broun, and communicated by Brisbane. |