OBSERVATIONS OF INGRESS OF VENUS. 495 



inserted the double-image micrometer, and got, at intervals during about 

 14 minutes, 13 measures of distances of limbs. These were caught in passing 

 glimpses ; but, owing to incessant variation in the Sun's brightness, they were 

 very irregular, and can be of little use. The Sun was never quite clear. I 

 append a list of times and measures ; but, as there was no opportunity of 

 measuring diameters for zero of micrometer, the measures can only be re- 

 ferred to the zeros as determined from the model the day before and the day 

 after the transit. 



At about 19 h . 28 m . the Sun was lost in a large mass of cloud, and further 

 measures of diameters were impracticable till too late to be of any use. I 

 therefore again compared the equatorial and transit clocks. Kain set in just 

 as this was finished and lasted till 21 h . 40'"., and the Sun never appeared 

 again till 10 minutes after the fourth contact, when it shone brightly until 

 nearly sunset. 



Nothing peculiar was noticed in the appearances near or after second 

 contact. They were just those for which the model when observed on a dull 

 day had prepared us ; though a certain amount of atmospheric vibration 

 made the Sun's limb and the planet rather tremulous. In good sunlight 

 there is no doubt that satisfactory micrometer-measures and satisfactory 

 observations of contact might have been made. The planet was intensely 

 black, with a sharp black outline. 



[It is remarkable that there is no allusion to a silvery ring round Venus. G. B. A.] 



EPITOME OF THE OBSERVATIONS OF THE TRANSIT OF VENUS, BURNHAM, N.. Z., 



1874, DECEMBER 9. 



Clock times were taken by Dent No. 2017, compared with the Transit- 

 Circle Arnold No. 2 before and after observations. 



b m B 



At 17. 44. Dent slow of sidereal time at transit hut = + 6'i3. 



,. 19. 5o. = + 6-32. 



(The correction from transit hut to equatorial hut is = -f o-o3.) 



h m s 



t 



Therefore at 17. 44. Dent slow of sidereal time at equatorial hut = + 6'i6. 

 19. 56. = + 6-35. 



The Adopted Longitude of Burnham is i i h . 29"". i3 s 'i East of Greenwich. 



3 s 



