/i52 PHILOSOPHICAL TRANSACTIONS. [aNNO 1794. 



pearance, and point out to me the place of the sky where he had seen the moon, 

 with respect to the opposite house and chimneys over which she appeared. With 

 the help of a pocket compass and small wooden quadrant, I found the bearing of 

 the place of the sky, which he pointed out to me, to be 80" west of the magnetic 

 south, or 56° west of the true south meridian, and the altitude 34°. Taking 

 the moon's right ascension from the nautical almanac for the 7th of March, the 

 day stated by Mr. Wilkins, with the bearing above-mentioned, and latitude of 

 St. John's-square taken 51° 31', I find the observation must have been made 

 exactly at 8 o'clock mean time, provided the bearing could be exactly depended 

 on ; but as an uncertainty of a few degrees may be allowed in this, we may con- 

 clude that the observation was not far from 8 o'clock. This agrees nearly with 

 the time of Mr. Wilkins's observation, for he seems to have lost sigiit of the star 

 on the dark part of the moon a little before 8 o'clock, mean time, at Norwich, 

 the correspondent time to which in St. John's-square, on account of the differ- 

 ence of meridians, would be 5 minutes sooner. An error only of 10 minutes in 

 the time noted by Mr. Wilkins, and that deduced from the bearing observed in 

 St. John's-square, both taken together, will bring the observation in St. John's- 

 square to precede the time of the disappearance of the star-like appearance at 

 Norwich : and therefore the 2 observations agree as nearly together as can be 

 expected from the circumstances in which the observers were placed, and the 2 

 observations mutually confirm each other. The altitude of the moon at 8 o'clock, 

 by computation, is 41°, or 7° higher than that taken with the quadrant ; which 

 difference may be allowed for the error such an estimation is liable to, and affords 

 no ground for argument against the observations belonging to the same pheno- 

 menon, and consequently is an additional confirmation of it. 



Mr. Vince, in his letter to me, giving me the first notice of this phenomenon, 

 observed that Mr. Wilkins is an eminent builder, a sensible man, and by no 

 means likely to be deceived ; and adds, that the length of time during which he 

 saw it, seems to preclude the possibility of any deception. Mr. Wilkins him- 

 self relates that he is long sighted, and that he distinguishes very well the dark 

 part of the moon, illuminated by a faint light, while she is young, which com- 

 pletes her circle. The other person, Thomas Stretton, is a young man of so- 

 briety and steadiness, and long sighted also. I particularly mention these cir- 

 cumstances, to obviate an objection that has been made to these accounts, from 

 the circumstance of the bright star in the south eye of the bull, called Adebaran, 

 having passed by the moon the same evening, and been eclipsed by the northern 

 part of her disc. I own it is a singular coincidence of circumstances, that Alde- 

 baran should the same evening pass behind the moon, in nearly the same track 

 in which this star-like appearance was observed on the dark part of the moon's 

 disc : but the 2 facts, considered as independent of each other, are not incom- 



