* 
Mr. Bowditch on the annular eclipse, April 3, 1791. 287 
Ferrer in the sixth volume of the same work. This gentleman sup- 
poses that the time of forming the annulus was marked too small by 
one minute, a mistake that might easily have been made, and of which 
several instances have occurred in the most important observations 
made by the best astronomers of Europe. This correction being ap- 
plied, makes the times of conjunction, deduced from the three obser- 
vations, agree much more nearly with each other than they otherwise 
would do. Ihave therefore adopted it in the following calculation. 
Using the tables of Delambre and Burg, correcting the moon’s longi- _ 
tude by adding 20”, and the moon’s latitude by adding 7’"6, which is 
necessary from the observation at Greenwich and Paris, mentioned in 
the former part of this memoir, the calculation becomes 
Mean time. ()-©) Par. lon. Par. lat. 
‘Formation of Annulus —_18/. 40’ 01” 25' 407 46’ 546 
Breaking of Annulus 18 43 15 25 36 °7 46 49 +2 
End of the eclipse 19 55 37'S 22 20 0 44 00°8 
The conjunction by the mean of these three observations is at 19h. 
37’ 00"-4 mean time, or 194. 33’ 42”°6 apparent time. The difference 
between this and the conjunction at Greenwich, calculated before 0. 
42! 002, is 5h. 8’ 176, the longitude of Georgetown, and as this 
place by the measurement of Seth Pease Esq. is 13°1 seconds, in time 
W from the Capitol in Washington, the longitude of the Capitol 
would be by this observation 54. 8’ 4"°5.. The observation of Mr. 
Pease on the eclipse of 1811, makes it in 5h. 8'11"*4.. The mean of 
both gives the longitude of the Capitol in Washington 5/. 8’ 80, 
whence the longitude of Georgetown is 5h, 8’ 21"1 = 77° 5' 16" W 
from Greenwich. | 
The observations of this eclipse at Philadelphia, given by Mr. 
a escitine 3 in vol. iii. page 154 of the Transactions of the American 
iano Saint. of sh 0% ube erroneous. For the 
o os ble 
*, 
