OF THE SUN, JUNE 16, 1806\ 273 



atmosphere of the earth, is 1980 times more than that of the 

 moon. — Wt must conclude that so rare an atmosphere cannot cause 

 any evaporation. 



Some of the lunar mountains are 1^ miles high, and we 

 can clearly perceive them with a telescope, which magnifies 

 100 times, and it is constantly observed, that the spots and in- 

 equalities of the superficies of the moon, are always seen in 

 the same form, whence it follows, that there can be no cloud 

 which covers even one mile in extent. Again, it has been ob- 

 served that the edges of the moon emit more light than the 

 centre, which is the very reverse of what happens in the sun, 

 comets and planets, of which the centres are more luminous 

 than the edges, on account of their being surrounded by at- 

 mospheres. 



It has appeared to me, that the cause of the illumination of 

 the moon, as noticed above, is the irradiation of the solar disk, 

 and this observation may serve to give an idea of the extension 

 of the luminous corona of the sun. Suppose then that there 

 is no density in the lunar atmosphere. — By the preceding cal- 

 culations, the apparent relative inclination of the orbits between 

 the interior contacts was 4° 49' 30", the duration of the total 

 obscurity 4' 37" and the relative apparent chord l' 4S" 16. 



Moreover, the illumination preceded the emersion 6" 8; we 



have therefore very nearly the irradiation of the semidiameter 



„ . 1' 48" 1(5 X 6" 8 



rf the o = ^ 4g . 3Q = 2" 6. 



No. XLIV 



Observations on the solar eclipse of June \6th, 1806, made at 

 Bowdoin College in the District of Maine. Communicated by 

 a member of this Society to Mr. John Vaughau. 



Read March &h, 1807. 



YOU ask for the result of the observations made at Bow- 

 doin College, (in the township of Brunswick and district of 



