Note 293 — MEMOIR OF THE LIFE OF DAVID RITTENHOUSE; CONTINUED, FROM THE TIME OF HIS SETTLEMENT IN PHILADELPHIA.

In the annular eclipse of the sun, on the 3d of April, 1791, as observed at Philadelphia by Mr. Rittenhouse, the formation of the ring is stated at 6h 46′ 11½″ A. M. true time; and its rupture, at 6h 50′ 28″. “I have,” says Mr. Lalande (in his Additions, 1797,) “reduced the conjunction of it to 7h 41′ 19″, and the difference of meridians 5h 10′ 3″, greater by 7″ than that given by Mr. Rittenhouse. This duration of the ring, gives for the latitude in conjunction 44′ 57″, which confirms the value of the diameters of the sun and of the moon, that I have given in the 3d edition of my Astronomy, and the diminution that I make in the eclipses, 3½″ for the ray of the sun, and 2″ for that of the moon. I have subtracted one minute of the time marked in the third volume of the Transactions of the Society of Philadelphia, for the formation and the rupture of the ring; but this correction was pointed out to me by the termination of the eclipse, as well as by the difference of meridians, which was ascertained by the Transit of Venus over the Sun.”