366 OF THE DISTANCES AND MAGNITUDES

F to / in her orbit* in the time she appears topass over the fun from K to L.

And the nearer the earth is to the fun, thegreater will the difference of the durations ofthe transit be, as seen from the earth’s surface,and from its center : and the further the earthis from the fun, the less will the difference be-tween the durations of the transit be, as seenfrom the earth’s surface, and from its center.For it is plain, from the first and second figures,that the nearer the earth is to the fun, thenearer also, in proportion, will it be to Venus $and the further it is from the fun, the furtheralso it must be from Venus. So that the spacethrough which the observer is carried, by theearth’s motion, will bear a greater proportion tothe distance of Venus from the earth, in theformer cafe than in the latter, and must there-fore affect the times of the durations of thetransit, as seen from the earth’s center, and,fromits surface, accordingly.

Now, as the apparent breadth of the sun isknown, and the time of Venus’s going roundthe fun is also known, the time of her appearingto move through a space equal to the fun’sbreadth is easily calculated, and is the fame aswould be observed by a person placed at rest atthe earth’s center. And as it appears, fromwhat has been said, that the difference of thedurations of the transit, as seen from the earth’s

surface,

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