i88 3 .] 
13 7 
The Constitution of the Sun. 
we may use the term) of light rays ? Is it on the assump- 
tion of unequal luminosity of the solid body of the sun . 
If so, then, how are we to account for the irregular direction 
of the rays ? If we were to assume refraction to be the 
cause, we would immediately be met by the fadt that lays 
evidently emanating from almost the same parts ot his sur- 
face appear to be oppositely affedted, the one group streaming 
out to the right, while the other goes to the left. Besides, 
even supposing such was not the case, we cannot but imagine 
that a medium, sufficiently dense to refraCt light so far oil 
its natural course, would have a tendency to reduce its 
intensity to that of the light emanating from the less 
luminous parts of the surface. On the hypothesis of the 
sun’s being a luminous body enveloped m clouds, li the 
cloudy covering were all. of the same density, and the solid 
of equal luminosity, there would be uniform radiant light , 
but if the solid were not uniformly luminous, and there weie 
breaks in the cloudy covering, then the unequal radiant light 
would be seen to be overlapped or crossed by bright sheals 
or streaks of light, proceeding from the openings, the direc- 
tion of such streaks depending on the positions ot the 
openings as regards the points of emanation of the hght. 
But whatever direction these rays of light originally took, it 
our theory be correct, they would eventually have to letuin 
to a direction in a line with the plane of the ecliptic, 
which probably accounts for their generally curved ap- 
pearance. .11 , u 
Next, with regard to solar heat, are we still to hold to our 
fiery theories, and see the sun as a gaseous or molten mass, 
the heat of which is maintained by condensation, friction, 
chemical aCtion, or the impaCt of other bodies ; 01 are we to 
account for his heat from one of our most stable laws, 
namely, that when force is retarded by matter , heat results . 
If we do so, then the force which we receive from the sun, 
call it what we will, must be retarded in its passage through 
the sun’s atmosphere ; therefore heat must result. P ar t 0 
this heat will be reflefted back to his surface, and part 
probably escape into interstellar space. Of this latter pait 
(if any) we will receive our share. But would this be sum- 
cient to account for all the heat that we receive at the 
earth’s surface ? I think not ; but I do think that it is here 
that the economy of Nature steps in. His heat is of no use 
in interstellar space, — it is the worlds circling 10U ^j “ im 
to which it is necessary ; consequently these worlds a ** e 
provided with a gaseous envelope like his own, which letards 
VOL. v. (third series). l 
