268 Mr. Bowshitch. on the solar eclipse, Sept. 17, 1811. 
6h. 57’ 06"*1 pene ‘the longitude of Nantucket 4h, 40’ 31"-6 = 70° 7 
54” West from Greenwich. 
| Mr. oe: Seer made several observations of the width of the lucid 
part of the sun during the eclipse. I selected two observations when 
the distance was the shortest, subject to the least change, most easy to 
measure and best adapted to ascertain the error of the moon’s tabular 
latitude. These observations were at 2h. 30/ 50" and 2h, 35’ a 
mean time. The measured distances were 4’ 58-9; 4’ 56”°6. The 
moon’s augmented semidiameter 14’ 51-03; 14’ 50’-92. Thesun’s 
semidiameter 15’ 53°77, Hence the apparent distances of the centres 
of the sun and moon (= measured lucid part + D’s semidiameter— 
©’s semidiameter) were 3’ 56’*16 and 3’ 5375. . The pardilaxes in» 
longitude ()—©) were—10' 00"-6 and—10' 30’°7; in latitude 41’ 
219 and 41’ 36”-5.. From these were deduced the apparent lati- 
tudes; and, by applying the parallaxes in latitude, the true latitudes 
37 35"-2 and 37’ 43:4 were obtained, which subtracted from the cor-__ 
responding tabular latitudes 37’ 44/4 and 37’ 55’°8 give the error of» 
the tables in latitude, by the first observation —9” ‘2; by..the sind 
—12"-4; the mean of both is —10’"8. a 
At Monticello, Virginia, by the Hon. Thomas Jefferson, late President 
Of the United States and President of the American shares en 
Society, Sept. 17, 1811. 
The two internal contacts are useful in finding the error nol the 
moon’s latitude. These observations are as is follow, the latitude being. 
38° 8° N, reduced 37° 56’ 52”, 
App. time. es eri long. Par.inlat. J) yt 
Annulus formed lhe 53’ 00) 5’ 582 . 36’ 51"-4 14’ Se 8 
Annulus broken 1 59 25 ~6 53 +5 SR1746 <a Saw 
j 
