Page:Philosophical Transactions - Volume 054.pdf/347

 the planet presently became distinct, and her limb well defined. Upon this, I applyed myself to observe the passage of the Sun's and Venus's preceding limbs, by the vertical, and of their lower limbs by the horizontal, wires in the reflector, and made the following observations; one of my assistants counting the clock, and the other writing down the observations as I made them; which, having made the proper correction of the time for the change of the Sun's declination, stand as follows.

As Venus began now to draw near the Sun's limb, I prepared to observe her egress. The interior contact did not appear so perfectly instantaneous, as Dr. Halley's papers led me to expect. I was not certain of it till 4$h$ 47′ 21″, though I doubted of it at 17″. The exterior contact I judged to be at 5$h$ 5′ 49″, doubtful also 3 or 4″; and so the passage of Venus's diameter, 18′ 28″.

The above observations gave me several altitudes and azimuths of Venus, from whence I deduced her Rh