THE SUN AND SOLAR PHENOMENA. 57 



the sun ; the penumbra is the cloudy interior surrounding stratum ; and the faculae, or 

 bright ridges, are accumulations of the exterior luminous matter, heaped up by the violent 

 local agitations. In its interior physical constitution, therefore, that magnificent phantom, 

 or globe of fire, which the ancients conceived the sun to be, is, in all probability, an opaque 

 substance, like the ground we tread upon ; and, correspondingly, the atmosphere of our 

 own globe is in a state of constant mutation. It is sometimes charged with clouds, which 

 will completely hide the surface from view at no considerable distance from it. These are 

 often rapidly rent asunder, gathered into distinct masses, and driven again into conjunction, 

 affording transient glimpses of the earth to the adventurous aeronaut ; circumstances which 

 are apparently analogous to the superficial solar changes, though comparatively upon a 

 most puny scale. 



If this view of the constitution of the central globe be correct, there are strong 

 resemblances between the sun and the bodies circulating in the system. They exhibit a 

 family -likeness, being opaque masses, having a motion of rotation, and rotating in the same 

 direction. In fact, according to Herschel, the sun appears to be nothing else than a 

 veiy eminent, large, and lucid planet, evidently the first, or rather the only primary 

 one of our system ; and because of this analogy, in regard to solidity, atmosphere, and 

 diversified surface, he was led to infer that it is most probably inhabited by beings whose 

 organs arc adapted to the peculiar circumstances of that vast globe. We feel it difficult 

 to embrace this conclusion, from the fact of the solar rays producing, at the distance of so 

 many millions of miles, a heat so considerable, that it must be intense and insufferable on 

 the sun's surface, inferred to be far greater than that of the strongest blast furnace. 

 But heat is only produced by the solar influence when it comes into contact with a 

 substance that combines with it. Various experiments and familiar circumstances prove 

 this to be the case. If the solar radiation collected in the focus of a powerful lens is 

 thrown into the air, and continued there for a considerable time, no sensible heat will 

 afterwards be perceived at the place, though had the most incombustible object been 

 exposed there, such as gold or platina, it would have been fused. The eternal snow rests 

 upon the summits of high mountains, which receive the direct influence of the sun's rays, 

 while in sheltered parts of valleys below, receiving only their indirect influence, there is 

 overpowering heat. The higher in the regions of the atmosphere an aeronaut ascends, 

 the more intense is the cold, though there is nothing to interrupt the solar influence. 

 Heat, therefore, is only generated by the sun's rays, when they unite with caloric, or 

 heat in a latent state. We may conceive, then, the temperature of the sun's luminous 

 atmosphere to be greater than that of any artificial heat which chemistry or galvanism 

 can produce ; yet the great globe itself may be constituted incapable of any chemical 

 combination with the rays of the brilliant atmosphere without, beyond a certain extent, 

 and if so, a temperature consistent with animal and vegetable life may there exist. 



It is not, however, unlikely that the penumbra of the spots, the stratum of dense 

 clouds below the vividly resplendent visible surface of the sun, may officiate to moderate 

 the effect of the exterior atmosphere. Sir John Herschel, referring to that inner curtain 

 of the mighty orb, remarks, " That the penumbral clouds are highly reflective, the fact of 

 their visibility in such a situation can leave no doubt." They may thus serve the purpose 

 of effectually defending the si-lar body from the insufferable light and heat of the outer 

 most surface, furnishing the solid nucleus of the luminary with a moderate temperature 

 by their friendly interposition. 



In the class of solar phenomena, Eclipses of the sun are always interesting, and 

 sometimes imposing events. Few occurrences have given rise to more anxious feelings in 

 the human breast, or have been watched with more unfailing curiosity. We are so familiar 

 with their physical causes, and can predict with such nicety the time of their appearance, 



