450 PHILOSOPHICAL TRANSACTIONS. [aNNO 1794. 



sion to consult Hopson's book a very few days before, and met with this particu- 

 lar passage, which I read with a determination to pursue the experiment at some 

 future period, but had neglected to do so. The moment I saw the cloth, the 

 similarity of circumstances struck me so forcibly, that I sent for the book and 

 showed it to Mr. Golding, who agreed with me that it appeared sufficient to ac- 

 count for the accident. However, to convince ourselves, we took a piece of the 

 same kind of cloth, wetted it with linseed oil, and put it into a box, which was 

 locked and carried to his quarters. In about 3 hours the box began to smoke, 

 when on opening it, the cloth was found exactly in the same condition as that 

 which had given us so much uneasiness in the morning, and on opening the 

 cloth, and admitting the external air, it burst into fire. This was sufficiently 

 convincing ; however, to make it more certain, the experiment was 3 times 

 tried, and with the same success," 



p. s. The passage Mr. Humfries alludes to, is in page 629 of Hopson's Che- 

 mistry, where, in a note, you will find mention made of a set of chemical ex- 

 periments made on inflammable substances by a Mr. Giorgi of the Imperial Aca- 

 demy of Petersburg in consequence of the burning of a Russian frigate at 

 Cronstadt in 1781, though no fire had been made on board of her for 5 days 

 before. 



XXVI. Of an appearance of Light, like a Star, seen in the Dark Part of the 

 Moon, on Friday the 7lh of March, 1794, by IVm. Wilkins, Esq. at Norwich. 

 p. 429. 



When I saw the light speck, as shown in the sketch, (see pi. 4, fig. 16) a few 

 minutes before 8 in the evening, I was very much surprized ; for at the instant of 

 discovery I believed a star was passing over the moon, which on the next mo- 

 ment's consideration I knew to be impossible. I remembered having seen, at 

 some periods of the moon, detached lights from the serrated edge of light, 

 through a telescope ; but this spot was considerably too far distant from the 

 enlightened part of the moon ; besides, this was seen with the naked eye. I 

 was, as it were, rivetted to the spot where I stood, during the time it continued, 

 and took every method I could imagine to convince myself that it was not an 

 error of sight ; and 2 persons, strangers, passed me at the same time, whom I 

 requested to look, and they said it was a star. I am confident I saw it 5 mi- 

 nutes at least ; but as the time is only conjectural, it might not possibly be so 

 long. The spot appeared rather brighter than any other enlightened part of the 

 moon. It was there when I first looked. The whole time I saw it, it was a 

 fixed, steady light, except the moment before it disappeared, when its brightness 

 increased ; but that appearance was instantaneous. 



