C 335 ] 
vvlth thick clouds all the afternoon, till a fhort time 
before the external contact; but they drove away 
towards the north, and left the Sun perfectly bright, 
excepting that now and then a cloud palled over 
him. But we foon found that the conftitution of the 
air was otherwife unfavourable to our obfervations ; 
the image of the Sun on the white board, made by 
the achromatic telefcope, was bright' enough; but 
there was a remarkable undulation in the limb, 
which could be owing to nothing elfe but the hate of 
the air. This inconvenience was alfo fenlibly felt 
both by the other gentlemen and myfelf. Befides 
the undulation now mentioned in the limb of the 
Sun, there was alfo a conliderable tremor round the 
planet Venus, when (lie was feen upon the Sun’s 
difc, and, in confequence of this, an indiftindnefs in. 
her limb, which made it impofTible to meafure her. 
diameter by our objed glafs micrometer, or other- 
wife. After the center of Venus had pafTed- the- 
Sun’s limb, flie appeared to us not to? be circular, 
but oblong, the longeft diameter being that which 
palTed through the Sun’s center. As the internah 
contad approached, Venus appeared to us to adhere 
to the Sun’s limb, by a dark protuberance or neck,, 
both the length and breadth of which varied every 
moment by a conftant undulation: neither did this 
neck break off inftantaneoufly, but changed its colour 
from black to a dufky brown, till at lafl: the interval 
betwixt Venus and the Sun’s limb appeared quite 
clear. Each of the obfervers wrote down. his obfer- 
vations on the fpot. I reduced them, together with 
my own, to apparent time, from the obfervations I 
bad. 
