ObserTation on the Planet Venus. 165 



Astronomy, it is said, when describing the phases of Mercury 

 and Venus, " their luminous side is completely turned to the 

 earth at the time of their superior conjunction, wlien they 

 would appear like the full moon, if they were not then eclipsed 

 by the rays of the sun:'' Other writers have expressed them- 

 selves in such language as the following: — "When Venus is 

 on the other side of the sun, in which she appears in the same 

 sign with him, she cannot be seen in the heavens, being lost in 

 the effulgence of the solar rays," &c. 



It is nearly thirty years since I published in Nicholson's 

 "Philosophical Journal" (vol. xxxvi. p. 109 — 128), and other 

 scientific periodicals, a series of observations made on the hea- 

 venly bodies in the day time, in which I shewed that Venus 

 could be seen w^hen within less than two degrees of the sun, 

 either to the east or to the west of that luminary, having 

 several times seen her in these positions ; and, consequently, 

 that she could be as easily seen at the same distance north or 

 south of the sun at the moment of conjunction. But I had no 

 opportunity of making this observation for many years, either 

 on account of a cloudy atmosphere, or of the planet being too 

 near the sun at the time of the conjunction. On the 2d of Oc- 

 tober last, the weather being favourable, the experiment was 

 tried and found successful. At two o'clock p.m. — only two 

 hours before the conjunction — I perceived the planet distinctly, 

 and kept it in view for nearly ten minutes, till some dense 

 clouds intercepted the view. It appeared tolerably distinct 

 and well-defined, though not brilliant, and with a round full 

 face, and its apparent path was distinctly traced several times 

 across the field of view of the telescope. I perceived it after- 

 wards, about half-past four p.m., only a few minutes after it 

 had passed the point of conjunction, on which occasion it ap- 

 peared less distinct than in the preceding observation, owing 

 to the low altitude of the planef, being then only a few degrees 

 above the horizon. The observations were made, not with an 

 equatorial instrument, which I generally use in such observa- 

 tions, but with a good achromatic teleseof>e 44^ inches focal 

 distance, mounted on a common tripod, with a terrestrial 

 power of 95 times. A conical tube, about ten inches long, 

 was fixed on the object end of the telescope, at the extremity 

 of which an aperture 1^ inch diameter, was placed, so as to 

 intercept, as much as possible, the direct ingress of the solar 



