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[[In left margin]]On the Transit of [[Venus symbol]] over [[Sun symbol?]] and the Sun's Parallax[[/margin]]

[[underline]]Remarks on the Times of the internal and external Contacts of the Egress of[[/underline]] Venus[[underline]] from the Sun, as observed by[[/underline]] M. Pingrè, at Rodrigues, [[underline]]in[[/underline]] 1761 [[underline]]Addressed to Astronomers; but especially to the[[/underline]] French[[underline]] Astronomers. By[[/underline]] PHILALETHES LONDONENSTS. 

   The times of the internal and external contacts of [[underline]]Venus[[/underline]] with the sun's limb, sent to the Royal Academy of Sciences at [[underline]]Paris[[/underline]], and to the Royal Society at [[underline]]London[[/underline]], are, 0^h 34^m, 47^S and 0^h, 53^m, 18^s. If we compare these times with the times of the same contacts as [[underline]]Tobolsk[[/underline]], the sun's parallax comes out by the first = 7, 36^s and, by the last, = 8,36^s and, if we compare the same times by [[underline]]Pingrè[[/underline]], with those made at the [[underline]]Cape of Good Hope[[/underline]], the results will be, = 11, 24^s and 8, 20^s. 

  If we compare the observations of the internal and external contacts at the [[underline]]Cape[[/underline]] and Tobolsk, the results will be, = 8,64^s and 8,32^s. 

   This, then plainly shews, that there must be a mistake in the time of the [[underline]]internal contact[[/underline]] at [[underline]]Rodrigues[[/underline]]; and we find that M. [[underline]]Pingrè[[/underline]], after his arrival at [[underline]]Paris[[/underline]], has altered his times both of the internal and external contact, giving this for his reason, in a letter to the Royal Society, "that his clock being slow, 1^m, 2^s he had, in the numbers before sent to [[underline]]Europe, subtracted[[/underline]] the 1^m, 2^s instead of [[underline]]adding[[/underline]] them." If, therefore, we allow this correction to be just, and compare these new times with the times at [[underline]]Tobolsk[[/underline]], the results of the sun's parallax, from these new numbers, will be, = 9, 98^s and 11, 23^s and by comparing them with those at the [[underline]]Cape[[/underline]], = 5, 66^s and 2, 90^s. This, therefore, again shews, that these new numbers are not the true ones, and that [[underline]]M. Pingre[[/underline]], being, perhaps, aware of this, has added 2^m, 2^s to the time of the internal contact, as sent to [[underline]]Europe[[/underline]]; and only 1^s 2^s to the time of the external contact, tho' in every other observation he has added 2^m 2^s, and the reason is plain, for if he had added the 2^m, 2^s also to his external contact, he had made the duration of the egress longer, by one whole minute, than it was observed any where else. 

   Upon the whole, may we not conclude, that, since the time of the external contact, as sent to [[underline]]Europe[[/underline]], agrees in giving the same parallax of the sun, with that given by all other observations of the same contact, and since the time of the internal contact, as given by [[underline]]M. Pingrè[[/underline]], since his arrival at [[underline]]Paris[[/underline]], disagrees with the results of other places, in the quantity of the Sun's parallax, there must needs have been an error of one minute, in the time of his nearest contact, as sent to [[underline]]Europe[[/underline]]; and that this contact should have been set down at 0^h, 35^m, 47^s? This being admitted, if we compare the times of internal and external contacts at [[underline]]Rodrigues[[/underline]], with the times of the of the same contacts observed at Tobolsk, the parallax of the sun comes out = 8, 62^s and 8,36^s, and, if compared with the times at the [[underline]]Cape[[/underline]], the results are, = 8, 54^s and 8, 20^s as will more fully appear from the following comparisons, in which the times of the internal and external contacts at the [[underline]]Cape[[/underline]], as they were sent to [[underline]]Europe[[/underline]], are compared with the times of the same contacts observed at eight different places in [[underline]]Europe[[/underline]], and the result of each comparison given; and the times at at [[underline]]Rodrigues[[/underline]] as sent by M. [[underline]]Pingrè[[/underline]], are also compared with the same place