Whence the contact was at 4h 5′ 51″ mean time; or 4h 21′ 2″ apparent time.
Eclipse of the Sun, January 9th, 1777.
The Gregorian Reflector, with the magnifying power of 95, was made use of for this Observation; which, as well as the Observation of the Transit of Mercury, was made in the College-Library, to which the Telescope belongs.
While Mr. Rittenhouse was endeavouring to adjust the two-f. reflector belonging to the Library of the city of Philadelphia, made by Short, and which had been borrowed on this occasion, I observed with the greatest certainty the first contact of ☾’s limb with the ☉, which was shining very bright, and the telescope in the best order, viz. at 8h 57′ 27″ per clock.
The same was visible, in about 3″ more, to Mr. Lukens, with the equal altitude instrument, magnifying about 25 times.
Mr. Rittenhouse had not got the other reflector ready to observe the beginning of the eclipse: but the end was observed by both of us to the same instant, viz. at 11h 48′ 50″ per clock.
The clock, at noon, was 23″ slower than mean time, whence
| Beginning of the Eclipse | 8h 49′ 55″ |  | Apparent time. |
| End of the same | 11 41 15 |
N.B. The clock stopped once during the Observation, owing, it was supposed, to the cold weather; but was oiled a little, and set a going again by a stop-watch that beats seconds, and which was set with the clock at the beginning of the eclipse: so that she lost no time. She was examined at noon, and found as above by the meridian mark. But this mark itself, having been lately shaken with the stormy weather, is to be re-examined, and also equal altitudes taken the following days.
The annexed micrometer measures were taken for determining the quantity of the eclipse, chiefly by Mr. Rittenhouse. More would have been taken, but the Sun was hid under clouds for about an hour after the middle of the eclipse, and broke out again a little before the end.