ASTRONOMY. 



side, filling a cubical space of 681,472,000,000,- 

 000,000 miles. If it would require 18.000 years 

 to traverse every square mile on the earth s sur 

 face, at the rate of thirty miles a day, (see p. 

 9,) it would require more than two thousand 

 millions of years to pass over every part of the 

 sun s surface, at the same rate. Even at the 

 rate of 90 miles a day it would require more 

 than 80 years to go round its circumference. Of 

 a body so vast in its dimensions, the human mind, 

 with all its efforts, can form no adequate con 

 ception. It appears an extensive universe in it 

 self; and, although no other body existed within 

 the range of infinite space, this globe alone 

 would afford a powerful demonstration of the 

 omnipotence of the Creator. Were the sun a 

 hollow sphere, surrounded by an external shell, 

 and a luminous atmosphere ; were this shell per 

 forated with several hundreds of openings into 

 the internal part ; were a globe as large as the 

 earth placed at its centre, and another globe as 

 large as the moon, and at the same distance from 

 tho centre as the moon is from us, to revolve 

 round the central globe, it would present to the 

 view a universe as splendid and glorious as that 

 which now appears to the vulgar eye, a uni 

 verse as large and extensive as the whole crea 

 tion was conceived to be, by our ancestors, in 

 the infancy of astronomy. And who can tell, 

 but that Almighty Being, who has not left a 

 drop of water in a stagnant pool without its in 

 habitants, has arranged a number of worlds with 

 in the capacious circuit of the sun, and peopled 

 them with intelligent beings in the first stages of 

 their existence, to remain there for a certain 

 period, till they be prepared for being transported 

 to a more expansive sphere of existence ? It is 

 easy to conceive, that enjoyments as exquisite, 

 and a range of thoughts as ample as have ever 

 yet been experienced by the majority of the in 

 habitants of our world, might be afforded to my 

 riads of beings thus placed at the centre of this 

 magnificent luminary. This supposition is, at 

 least, as probable as that of the celebrated Dr. 

 Herschel, who supposed that the exterior surface 

 of the sun was peopled with inhabitants. For, 

 if this were the case, the range of view of these 

 inhabitants would be confined within the limits 

 f two or three hundred miles, and no celestial 

 jody, but an immense blaze of light, would be 

 visible in their hemisphere. Such is the variety 

 which appears among the works of God, and 

 such is the diversity of situations in which sen 

 sitive beings are placed, that we dare not pro 

 nounce it impossible that both these suppositions 

 may be realized. 



Though the sun seems to perform a daily cir 

 cuit around our globe, he may be said, in this 

 respect, to be fixed and immoveable. This motion 

 is not real, but only apparent, and is owing to 

 the globe on which we are placed moving round 

 its axis from west to east ; just as the objects on 



17 



the bank of the river seem to move in a contrary 

 direction, when we are sailing along its stream 

 in a steamboat. The only motion which is 

 found to exist in the sun is, a motion of rotation^ 

 like that of a globe or ball twirled round a pivot 

 or axis, which is performed in the space of 25 

 days and 10 hours. This motion has been as 

 certained by means of a variety of dark spots 

 which are discovered by the telescope on the 

 sun s disk ; which first appear on his eastern 

 limb, and, after a period of about thirteen days, 

 disappear on his western, and, after a similar 

 period, reappear on his eastern edge. These 

 spots are various, both in number, in magnitude, 

 and in shape : sometimes 40 or 50, and some 

 times only one or two are visible, and at other 

 times the sun appears entirely without spots. 

 Most of them have a very dark nucleus, or cen 

 tral part, surrounded by an umbra, or fainter 

 shade. Some of the spots are as large as wouid 

 cover the whole continent of Europe, Asia, and 

 Africa, others have been observed of the size of 

 the whole surface of the earth ; and one was seen, 

 in the year 1779, which was computed to be 

 more than fifty thousand miles in diameter. 



With regard to the nature of this globe it 

 appears highly probable, from the observations of 

 Dr. Herschel, that the sun is a solid and opaque 

 body, surrounded with luminous clouds which 

 float in the solar atmosphere, and that the dark 

 nucleus of the spots is the opaque body of tho 

 sun appearing through occasional openings in 

 this atmosphere. The height of the atmosphere, 

 he computes to be not less than 1843, nor more 

 than 2765 miles, consisting of two regions ; that 

 nearest the sun being opaque, and probably re- 

 sertbling the clouds of our earth ; the outermost 

 emitting vast quantities of light, and forming the 

 apparent luminous globe we behold. 



The sun is the grand source of light and heat, 

 both to the earth and to all the other planetary 

 bodies. The heat he diffuses animates every 

 part of our sublunary system, and all that vari 

 ety of colouring which adorns the terrestrial land 

 scape is produced by his rays. It has been 

 lately discovered, that the rays of light, and the 

 rays of heat, or caloric, are distinct from each 

 other; for, it can be demonstrated, that some 

 rays from the sun produce heat, which have no 

 power of communicating light or colour. The 

 greatest heat is found in the red rays, the least 

 in the violet rays ; and in a space beyond the 

 red rays, where there is no light, the tempera- 

 lure is greatest. The rays of the sun have also 

 been found to produce different chymical effects. 

 The white muriate of silver is blackened in the 

 violet ray, in the space of 15 seconds, though the 

 red will not produce the same effect in less than 

 20 minutes. Phosphorus is kindled in the vici 

 nity of the red ray, and extinguished in the vici 

 nity of the violet. The solar light, therefore, 

 consists of three different orders of rays, one 



