Meteorological observations and essays / By John Dalton.

  • Dalton, John, 1766-1844.
Date:
1834
Catalogue details

Licence: Public Domain Mark

Credit: Meteorological observations and essays / By John Dalton. Source: Wellcome Collection.

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    formed an hypothesis to account for the aurora borealis by magnetism ; in the Abridgment by Jones, Vol. 4, part 2, we find, that the Doctor, after enumerating particulars of several appear- ances, conjectures that they are occasioned by the earth’s magnetism ; and he endeavours to illustrate the hypothesis by placing a feredla, or spherical magnet, with one of its poles upon an horizontal plane strewed with steel filings, which being done, the filings form various straight lined and curvilinear figures, according as they are situate near to or distant from the magnetic pole; these he thinks are analogous to the beams of the aurora borealts. The hght of the aurora he is pretty much at a loss to account for, as electricity was then but imper- fectly known.—If these hints of his had been pursued by others, the fact would undoubtedly before this have been established, that the beams of the aurora borealis are governed by the earth's magnetism ; but instead of this, philosophers have amused themselves and others with form- ing various other theories to account for the phenomena, most of which are extravagant, not to say ridiculous; M. Mairan’s zodiacal lght not excepted. Notwithstanding what the learned