Page:Philosophical Transactions - Volume 001.djvu/160

This page has been validated.

(151)

consent in what has been just now declared, & the Controversie being about Matter of fact, wherein Authority, Number, and Reputation must cast the Ballance, Mons. Hevelius, who is as well known for his ingenuity, as Learning, will joyn and acquiesce in that sentiment.

Of a Correspondency, to be procured, for the Finding out the True distance of the Sun and Moon from the Earth, by the Paralax, observed under (or neer) the same Meridian.

Seeing that the knowledge of this distance may prove of important Use, for the Perfecting of Astronomy, and for the better establishing the doctrine of Refractions; it is in the thoughts of some very curious Persons in England, for the finding out the same, to settle a Correspondency with some others abroad that are understanding in Astronomical matters, and live in places farr distant in Latitude, and under (or near) the same Meridian.

To perform which, the following Method is proposed to be observed; viz. That at certain times agreed on by two Observatours, making use of Telescopes, large, good and well fitted for this purpose, by a measuring rod, placed within the Eye-glass at a convenient distance, that it may be distinctly seen, and serve for measuring small distances by minuts and seconds (which is easie enough in large Telescopes) that, I say, each of such observers, thus furnish't, shall observe the visible way of the Moon among the Fixt stars, (by taking her exact distance from any Fixt starr, that lyes in or very near her way, together with the exact time of her so appearing) and the then apparent Diameter of her Disk; continuing these Observations every time for two or three hours, that so,

if