Viewing page 410 of 504

4. It is true that because the [[underlined]]Phasses of Venus and of Mercury[[/underlined-- change but slowly, and also because their apparent Diameters are but small; those Conclusions may not be depended upon, as if they were nice and altogether certain. The same thing may be said of proper Observations of the [[underlined]]Phases of Mars.[[/underlined]]

5. But, in ye Observations of the Dichotomys of the Moon, the Case is not so. For the apparent Diameter of the Moon exceeds commonly half a Degree; and may be still vastly increased, by means of Telescopes. And on the other hand, the Synodic Revolution of the Moon is so quick, as not to amount to thirty Days: Which Suiftness enables us to determine more nicely the Time of her Dichotomys. Nay the Sun's very small Parallax, in reference to the Planets of [[underlined]]Saturn[[/underlined]] and [[underlined]]Jupiter[[/underlined]], might in like manner be determined from those globes, by the Dichotomys of their outermost Satellites, or of some Comets passing near them.

6. The greatest possible Distance of the Moon from us, at the Time of her dichotomy, affords so considerable a Basis, not to mention the Encouragement which my former Discourses give us; that I hope that, even here at [[underlined]]Worcester[[/underlined]], the very great Parallax of the Sun may be verified in a few years, by Dichotomys observed with proper Telescopes.

7. Mr [[underlined]]Daugharty[[/underlined]] Senior observed the Section of the Moon on the 15th of this month of 
Please note that the language and terminology used in this collection reflects the context and culture of the time of its creation, and may include culturally sensitive information. As an historical document, its contents may be at odds with contemporary views and terminology. The information within this collection does not reflect the views of the Smithsonian Institution, but is available in its original form to facilitate research. For questions or comments regarding sensitive content, access, and use related to this collection, please contact