256 Mr. Bowilitch’s observations of the solar eclipse, Sept. 1811. 
limb where the first contact took place was brought in the centre of 
the field of view, and kept there till the first impression on the limb 
was observed at 114. 42’ 36” per chronometer. The end of the 
eclipse was at 2/, 46’ 18” per chronometer. ‘The first contact ap- 
peared to be instantaneous ; it seemed as if there could not have been 
an error of 1” in this time. The end was not quite so well defined; 
the moon appeared to remain 2” or 3” on the sun’s limb. Fahren- 
heit’s thermometer in the shade stood at 71° at 14. P.M; at 2h. 43' 
the mercury had fallen four degrees, and at 44. had again risen to 71% 
The chronometer at noon Sept. 17 was too slow for apparent time 
1A. 12’ 37"*1, and the daily variation was 30’-4. A proportional part 
corresponding to the beginning of the eclipse is 12, and at the end 
5”; making the chronometer too slow at those times 1/4. 12’ 383 
and 14, 12’ 42”°1; which, added to the observed times, give 
Beginning of the eclipse OA. 55’ 143 easienie time. 
End of the eclipse 3 59 00+1 
The latitude of the place of observation is 42° $3’ 30” NY The 
longitude 53 seconds in time East from Harvard Hall in Cam- 
bridge, as found by a trigonometrical survey, made by Professor Far- 
rar from Cambridge to Boston Light-House, and by myself from the 
Light-House to Salem. This agrees with the calculation of Seth 
Pease, Esq. from his survey of the Post Roads, and accords very 
nearly with Holland’s map. | 
The eclipse was also carefully observed at Salem, by Mr. Sam- 
uel Lambert, at a place, which by measurement was found to be 6” 
N and 27 in time E from the place where my observations were 
made. Hence the place of this observation is in the latitude of 42° 
33’ 36” N, and in the longitude of 55’*7 E from Cambridge. The 
chronometer used by Mr. Lambert was an excellent one, made by 
