Monday, January 23, 2012

from The London Magazine, 1784

(page 120)

Portion of a letter from Mr. Aepinus, Counsellor of State, in Russia, to Mr. Pallas, Counsellor of the Imperial College at St. Petersburgh, in consequence of the communication relative to a volcano in the moon discovered by Mr. Herschell, F.R.S., made to the Imperial Academy of Sciences, by Mr. De Magellan, member of the same Academy, May 4, 1783.


Nothing could have given me greater pleasure than the communication which I received from you respecting Mr. Herschell's discovery of a volcano burning in the moon. However interesting this observation may be to every lover of natural philosophy, it affects me still more particularly, as the fact when confirmed will demonstrate the truth of my Conjectures concerning the Volcanic Origin of the Inequalities in the Moon's Surface, which conjectures were formed in the year 1778, and published in a memo printed at Berlin in the year 1782.

(Footnote to letter referencing luminous spot on the moon ...)

† It was on the 11th of October, 1772, when the nephew of the late Professor Beccaria discovered a luminous spot on the moon during its total eclipse of that night; the professor having left his nephew and his sister at this own electrical observatory in Cartegna, where he intended to observe that eclipse, but was prevented, by receiving notice of the arrival of M. de Sauffure at Mondavi, where the professor went immediately to meet that philosopher, leaving his nephew with a small achromatic telescope of Dollond, with proper instructions to make the observation of that eclipse. Both the nephew and his sister did clearly distinguish a luminous spot in or near the place marked Copernicus on the moon's maps; and henceforth Professor Beccaria mentioned this observation in his public lectures of natural philosophy, to show that the round cavities of the moon's surfaces were as many craters of extinct volcanos.

... The reader may see this account given by the professor himself, in a letter directed to the Princess Josephina de Savoy-Carignan, where he delivers his opinion concerning that luminous appearance observed by Don Ulloa on the moon, during the total eclipse of the sun on the 24th of June, 1778, contending that such a luminous spot was a volcano actually burning, and not a real hole through the mass of the moon, as Don Ulloa had assumed to be the case.

... But it deserves to be remarked, that the two volcanos observed by Don Ulloa, and by the nephew of Professora Beccaria, must have been of an amazing size, both being discernible by small telescopes.

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