Page:Philosophical Transactions - Volume 054.pdf/348

 right ascensions and declinations; and from them, her longitudes and latitudes. The result of the whole, or the planet's difference in longitude from the Sun's centre and her latitude, is set down above, against each observation of Venus.

From hence I concluded that at the central emersion, which I put at 4$h$ 56′ 38″, the difference of longitude was 11′ 19, and the latitude 11′ 6″. Also, that the conjunction in longitude happened at 2$h$ 4′ 36″, the planet's latitude then being 9′ 28″.

In these calculations, I supposed the semidiameter of the Sun to be 15′ 50″, and of Venus 29″.

By several observations, I found the latitude of the place 47° 32′ N; which falls within the latitudes laid down in several books and maps, which make it from 47° 25′ to 48° 0′. I could make no use of Jupiter's satellites in finding the longitude, as they were not risen high enough to be observed above an hour before day-light came on. There were but two of their eclipses that could have been visible there while I was on the island; and though I watched for both of them, I was disappointed of both by unfavourable weather. Neither was I fortunate enough to get so much as one occultation of a fixed star by the Moon, though I spared no pains for it. The only observation I could get for this purpose was of the right ascension of the Moon, which I endeavoured to find, by comparing with that of a fixed star. But whether any mistake was committed in counting the clock, or in writing down the observations, or whether the position of the telescope was disturbed by any accident in the interval between the Moon's and star's passing, I am not able now to say. However, as I am sensible that