672 PHILOSOPHICAL TRANSACTIONS. [aNNO I769. 



tainly at that time some seconds must have been passed from the beginning of 

 the ingress. Therefore, I am very well persuaded, that 8^ 24™ g* apparent time, 

 which I took for the beginning of the ingress, is 4, 5, or 7 seconds too late. I 

 hoped to see the internal contact with more certainty; but I was mistaken; for I 

 found as great difficulty there, though of another kind. When I judged, by 

 means of the circular figure of the sun's disk, that Venus should be entirely 

 within the sun, I could not yet see the luminous cusps of the sun join together 

 behind Venus, who on the contrary appeared to carry the limb of the sun along 

 with her, which appeared to bend towards Venus, leaving a black cavity in his 

 limb ; and a moment after, when I thought I saw the whole body of Venus in 

 the sun, a little black column appeared to proceed from Venus towards the ima- 

 ginary limb of the sun. The whole of this phenomenon was certainly, in my 

 opinion, the effect of the tremors of the limbs of the sun and Venus ; but I took 

 8h 4iin 48S fQj. t]^g moment of the internal contact, when the thread of the sun's 

 light closed behind Venus. 



The limbs of Venus were at least as tremulous and ill defined as those of the 

 sun. Sometimes Venus had black eminences, which projected so much that they 

 were not unlike a pointed truffle. The first notch made by Venus in the sun 

 was not round, but resembled an obtuse angle. The diameter of Venus, which 

 was perpendicular to the sun's limb, appeared the greatest while Venus was pass- 

 ing over the sun's limb ; but after Venus had passed the sun's limb, the same 

 diameter appeared the smallest; so that Venus presented herself in both these 

 cases under an oval form, but in contrary directions. 



Clouds hindered us from observing the beginning of the eclipse of the sun ; 

 but I observed the end of the eclipse, at lOl^ 4"" 53' ap. time, with an achro- 

 matic telescope of DoUond, of 10 feet, magnifying 96 times; the same telescope 

 which I used in observing the transit of Venus. The difference of meridians 

 between Stockholm and Upsal is l" 40' of time. 



Lf^IIl. Observations of the Transit of Venus over the Sun, on June 3, 1769; 

 and the Eclipse of the Sun the next Morning; made at East Dereham, in 

 Norfolk. By the Rev. Francis IVoUaston, F.R.S. p. 40/. 



The telescope Mr.W. used was a reflector of Short's, of 12 inches focus, with 

 a power that magnifies about 55 times. His clock was made by Holmes. It 

 escaped dead seconds, had a pendulum with a wooden rod, and was firmly fastened to 

 a stack of chimneys in the room where he made his observations. He regulated it 

 by transits of the sun and stars, taken with a transit instrument of a peculiar kind ; 

 and also by equal altitudes of the sun, taken with another instrument of his own 

 make. By several transits of the sun and fixed stars, observed in the latter end of 

 May and the beginning of June, he had brought it to go at the rate of mean solar 



