PORTION OF THE COSMOS. THE SUN. 271 



is inclined 7J to the Ecliptic. According to Laugier's 

 very careful observations (Comptes rendus de 1'Acad. des 

 Sciences, T. xv. 1842, p. 941), the time of rotation is 

 25.34 days (or 25 days, 8 hours, 9 minutes), and the incli- 

 nation of the Equator is 7 9' 



The conjectures respecting the physical character of the 

 Sun, at which modern astronomy has gradually arrived, are 

 founded on long and careful observation of changes seen to 

 take place in the luminous disk. The order of succession 

 and the connection of these changes (i. e. the apparent for- 

 mation of the solar spots and the relation of their centres or 

 nuclei of deep black to surrounding ashy grey penumbras), 

 have led to the supposition that the actual body of the solar 

 orb is itself almost entirely dark, but encompassed at a 

 considerable distance by a luminous envelope, in which 

 funnel-shaped openings are produced by the action of cur- 

 rents from below upwards, and that the black nuclei of 

 the spots are portions of the dark body of the Sun seen 

 through these openings. In order to make this explanation 

 (which is here noticed in a cursory manner and only with 

 the greatest generality), account more satisfactorily for the 

 various particulars of the observed phenomena, there are 

 assumed, in the present state of our knowledge, three solar 

 envelopes : first, an inner cloud-like vaporous envelope ; over 

 this the luminous envelope (photosphere) ; arid above this 

 again (and as apparently indicated more particularly in the 

 phenomena of the total solar eclipse of the 8th of July, 1842), 

 an external vaporous envelope, either dark or only very 

 faintly illuminated ( 465 j. 



As happy anticipations and imaginations, long antecedent 

 to all actual observation, sometimes contain the germ of 

 true views, (Grecian antiquity is full of instances of such 



