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a fuppofed direction of her tranfit line, or path over 
the fun. 
About half an hour after feven, the clouds difperfed, 
and we had the fun perfe&ly clear during the re- 
mainder of the tranfit. When Venus approached the 
internal contact, I took off the micrometer, and 
changed the magnifying power of the telefcope, 
which, during the meafurements, had been that of 
70 times, into another of 140 times, and with this 
magnifying power, I obferved the internal contact; 
in which, I think, I cannot have erred fo much as 
two feconds, for the air was extremely clear, and at 
reft. With the fame magnifying power, I obferved 
the total exit ; and I do not think I have erred in 
this above five feconds, though this is a more uncer- 
tain obfervation than the former, and can by no 
means be determined fo accurately as the internal 
contact; and what I have erred in this laid obferva- 
tion, is rather in excefs, in making the exit too late. 
I have mentioned, above, the magnifying power 
of the telefcope I ufed ; becaufe I have found, by 
experience, that the different lengths of telefcopes, 
their different magnifying powers, and their different 
goodnefs, as well as the different goodnefs of eyes, 
want of practice, and different ffate of the air, will 
produce differences of times in thofe fort of obferva- 
tions. 
Thefe obfervations were made in the prefence of 
his Royal Highnefs the Duke of York, accompanied 
by their Royal Highneffes Prince William, Prince 
Henry, and Prince Frederick; her Royal Highnefs 
Lady Auguffa was pleafed likewife to do us the ho- 
nour of looking at this uncommon appearance. 
Times 
