It is curious that Galileo was inclined to account for the parallel direction of the earth's axis, on the supposition of a distant magnetic point of attraction in space. Without entering upon the consideration of a question which we usually refer to dynamical principles, yet it is pretty certain from recent observations, that both the sun and moon do exert an influence upon the magnet, and philosophers are strongly disposed to connect the variable phenomenon of the spots on the sun with the magnetic condition of our earth.
For further and more complete information on this subject, and subjects closely allied to it, the reader is referred to the following authorities : Humboldt's Cosmos,' Sabine's translation; Somerville'a Connection of the Physical Seiences ; ' Young's Lectures on Natural Philosophy ; ' Brewster's Magnetism ; ' Faraday's Researches; ' `Reports of the British Association for the Advancement of Science, on Magnetism and Meteorology;' ` Philosophical Transactions' of the Royal Society; Barlow on Magnetic Attractions ; " Annuaire Mag n4tique ' St. Petersburg, 1336; Gauss, on the General Theory of Terrestrial Magnetism, in Taylor's Scientific Memoirs,' August, 1839 ; Gauss and Weber's 'Magnetic Atlas,' Leipzie, 1840; Report of the Committee of Physics of the Royal Society ; " Magnetical and Meteo rological Instructions of the Royal Society;' ` Maguetical and Meteo rological Observations made at different Observatories, and printed by direction of the British and Foreign Governments, and the Honourable East India Company.'
Amongst those who have enriched this science ,by their investigations and observations, we may make especial mention pf General Sabine, to whom, in conjunction with Sir John Herschel, and the present Astrono mer Royal, is due the establishment of magnetic observatories and well organised expeditions, which have furnished upwards of 2,000,000 of observations in the course of three years, and who has, ever since the year 1819, devoted himself to the cause of terrestrial magnetism.
But terrestrial magnetism it still in its infancy ; much remains to be done ; and so simple and inexpensive are the methods and instruments of observation, that many would find a delightful and profitable amusement in the study—especially in the observance of magnetic storms—and thus contribute their mite towards the discovery of " the great ocean of truth."