ANNALS 



OF 



PHILOSOPHY. 



AUGUST, 1826. 



Article I. 



An Account of a curious Phmiomenon observed in the Moon. 

 By the Rev» J. B. Emmett. 



(To the Editors of the Annals of Philosophy.) 



GENTLEMEN, Great Omthum, near BorougftbrMge, July 5, 1826. 



The following communication will, perhaps, be interesting t© 

 some of your readers : the observations were made with the 

 greatest care, and with a very fine telescope. 



On the 12th April, 8^, whilst observing that part of the moon 

 called Palus Maeotis by Hevelius, with an excellent Newtonian 

 reflector, which has an aperture of six inches, and which bears 

 a beautifully distinct power of 800, and upwards, the most 

 southerly of two spots in Maeotis, called Alopecia by Hevelius, 

 and the most northerly, not noticed by Hevelius or Cassini, but 

 which is included in Russell's beautiful maps, were seen as 

 usual. Between, and very nearly in a right hue joining them, 

 but nearest to the N spot (the distance from the N spot being 

 about one-fourth that from the S) appeared a very conspicuous 

 spot, wholly enveloped in black nebulous matter, which, as if 

 carried forward by a current of air, extended itself in an easterly 

 direction, inclining a little towards the 

 S, rather beyond the margin of Maeotis. 

 The powers used were 70 and 130 ; the 

 state of the air was such, that greater 

 magnifying powers could not be employed 

 with advantage. 



April 13*^, 8'* to 9^; the cloudy appear- 

 ance was reduced, both in extent and 

 intensity : the spot from which it seemed 

 to issue, had become more distinctly 

 visible; it resembles the small circular, 

 or if near the limb, as in this instance, 



New Series, \ Oh, x\\. g 



