XIX. The Bakerian Lecture.—On the influence of the moon on the magnetic declination at toronto, St. Helena, and Hobarton

Publisher Website
Google Scholar
Abstract
The success which attended the endeavour to detect the influence of the moon on the pressure of the atmosphere, by a suitable arrangement of the hourly barometrical observations at St. Helena, naturally suggested the idea that the influence of the moon on the direction of the magnetic needle, supposing such an influence to exist, might be manifested by an analogous arrangement of the hourly magnetical observa­tions at that station; inasmuch as the magnetical disturbances due to other causes, and liable to mask so small an effect as that which might be anticipated from the moon, were, like those of the barometer, of inconsiderable amount at St. Helena when compared with those at many other stations. An examination of observations of the Declination made at Milan, whilst M. Kreil was Director of that observatory, led him, in a memoir read in February 1841 to the Royal Bohemian Society of Sciences, to announce his belief that the moon does actu­ally exercise an influence on the magnetic direction at the surface of our globe, cognisable by a variation in the Declination depending on the moon’s hour-angle, and completing its period in a lunar day. M. Kreil has since confirmed the discovery thus announced by investigations based on a more extensive series of similar obser­vations made under his direction at Prague, and discussed,— 1st, in the 'Magnetische und Meteorologische Beobachtungen zu Prag’ for 1841; and 2nd, in a memoir pre­sented to the Imperial Academy of Sciences at Vienna in June 1850, and published in the Transactions of that Academy in 1852.

This publication has 0 references indexed in Scilit: