NOTES. Ixiii 



Germany. A ** magnetic union," of which Gottingen was the centre, was 

 thus established, making simultaneous observations four times a year, be- 

 ginning from 1836, for periods of 24 hours. The appointed days, which 

 were called " magnetic term days," did not coincide with the epochs which I 

 had adopted and proposed in 1830, viz. those of the equinoxes and solstices. 

 Great Britain, thongh the nation which possesses the greatest trade and most 

 extensive navigation of the world, had hitherto taken no part in the movement 

 which, since 1828, had begun to promise such important results towards the 

 establishment of the science of terrestrial magnetism on a sure basis. In 

 April, 1836, by a request, addressed in a public manner directly to the then 

 President of the Royal Society of London, the Duke of Sussex, (Lettre de M. 

 de Humboldt a S. A. R. le Due de Sussex sftr les moyens propres a perfec- 

 tionner la connaissance du magnetisme terrestre par 1'etablissement de station* 

 magnetiques et d' observations correspondantes), I had the happiness of es~ 

 citing in those who had so much in their power a feeling of interest in an 

 undertaking the enlargement of which had long been the object of my warmest 

 wishes. In this letter I urged upon the Duke of Sussex the establishment of 

 permanent stations in Canada, St. Helena, at the Cape of Good Hope, in the 

 Isle of France, in Ceylon, and in New Holland, all localities which, five years 

 previously, I had pointed out as desirable. A joint physical and meteorological 

 committee, appointed by the Royal Society irom among its Fellows, proposed 

 to the government the establishment of fixed magnetic observatories in both 

 hemispheres, and, in addition, the equipment of a naval expedition for magnetic 

 observations in the Antarctic Seas. I need not here dwell on how deeply 

 science Is indebted to the great and zealous exertions, on this occasion, of 

 Herschel, Sabine, Airy, and Lloyd, and to the powerful support of the British 

 Association for the Advancement of Science at its meeting at Newcastle In 

 1838. In June, 1839, the magnetic Antarctic expedition was determined on, 

 and placed under the command of Captain James Clark Ross. It has now 

 returned, crowned with success and honour ; having enriched science with 

 most important geographical discoveries in the vicinity of the Southern Pole, 

 with simultaneous observations on eight or ten magnetic term days, [and with 

 a determination of the lines of equal Declination, equal Inclination, and equal 

 Force, over three-fourths of the accessible portion of the high latitudes of the 

 southern hemisphere. EDITOR.] 



( 167 ) p. 179. Instead of attributing the internal heat of the Earth to the 

 transition from a nebulous to a solid state of the matter of which it is formedj 

 Ampere proposes what appears to me a very improbable hypothesis, in which 



