305 
XL. 
ASTRONOMICAL OBSERVATIONS MADE NEAR THE CENTRE 
OF THE VILLAGE OF DEERFIELD, MASSACHUSETTS. 
BY EPAPHRAS HOYT. 
Communicated in a letter to Professor Farrar. 
1 D 
1. On the eclipse of the Sun of Sept. 17, 1811. 
THE telescope used in observing this eclipse was a 2} feet ach- 
romatic, magnifying about 75 times, with a pearl micrometer, made 
by” W. Jones, London. The times were noted by a very good metal 
clock, with a second hand, regulated on the 17th, 18th, and 19th of 
September by equal altitudes of the sun’s lower limb, observed with 
a best ten inch metal sextant, divided by a nonius to 30”; the equa- 
tion of equal altitudes being applied. The results of these observa- 
tions are 
1811 Sept. 17, time of apparent noon per lock, by” | m 
. ‘* mean of 4 statues J 11h. 57 27" 
18, . % 3 er oe 37 +20 
19, : ES . 11 +50 
Beginning ue the clipe per see - - Oh, 43’ 4” 
End - - 3 4759 
The greatest difference of the observations on the 17th from the 
mean was 6”; on the 18th 18”; on the 19th 9”. Those observations 
made on the 18th were not so good as on the other days. The morn- 
ing was so foggy, that the observations could not be made, till the sun 
was rather too near the meridian; and the day being windy, molasses 
was used for an artificial horizon, which gave but an ill defined image 
of the sun’s limb. The daily rate of the clock will therefore proba- 
bly be obtained enast accurately by the observations of the 17th and 
