Mr. Folger’s observations of the solar eclipse, Sept. 1811. 253 
serving. ‘On the 18th at 8A. 16’ 42-43 A.M. mean time, by the 
mean of eight altitudes, the clock was too slow for mean time 6’ 9°18. 
The morning of Sept. 17 was clear, with a small air from the 
SE: In the afternoon it shifted to W S W, and blew fresher. With 
the abovementioned telescope and a power of 26, I noted the begin- 
ning of the eclipse at OA. 51/9” per clock: Capt. Latham Gardner 
with a small spy-glass, with a power of 8 or 10, noted the beginning 
at Oh. 51’ 24”; which, reduced to mean time, give 
By my observation 0h. 56 388 
Capt. Gardner’s obs. 0 56 53 '8 
I noticed a tremulous motion of the sun’s limb, which rendered 
the observation of the beginning not so certain as I could have wish- 
ed. This was not observed by Capt. Gardner ; perhaps it was owing to 
the small power of his glass. At the end, the sun’s limb appeared 
perfectly distinct and steady. I noted the end at 3h, 54’ 16”, Capt. 
Gardner at 34, 54’ 7’, and Capt. Joseph Allen, with the inverting tel- 
escope belonging to a sextant, at 3h. 54’ 16"; which, reduced to mean 
time, are | 
By my observation 3/, 59’ 52” — 
Capt. Gardner’s 3° 59 43 
Capt. Allen’s 3. 59 52 
Near the end of the eclipse I observed the light of the sun to follow 
the moon as at Aand B, Plate II, Fig. 1, so that the limbs of the sun and 
moon did not make an acute angle at Aand B. The two projections of 
light, which in the figure are black at A and B, drew nearer and nearer, 
until they entirely coincided, and then they seemed to spring together in 
an instant, and the sun’s limb appeared perfectly well defined, which 
was the time I noted for the end. When I mentioned this appear- 
ance to Captains Gardner and Allen, after the eclipse had ended, they 
32 
