Suppose we had stood on the dome of Boston Statehouse November 9th, 1872, on the night of the great conflagration, and seen the fire break out; seen the engines dash through the streets, tracking their path by their sparks; seen the fire encompass a whole block, leap the streets on every side, surge like the billows of a storm-swept sea; seen great masses of inflammable gas rise like dark clouds from an explosion, then take fire in the air, and, cut off from the fire below, float like argosies of flame in space.  Suppose we had felt the wind that came surging from all points of the compass to fan that conflagration till it was light enough a mile away to see to read the finest print, hot enough to decompose the torrents of water that were dashed on it, making new fuel to feed the flame.  Suppose we had seen this spreading fire seize on the whole city, extend to its environs, and, feeding itself on the very soil, lick up Worcester with its tongues of flame—­Albany, New York, Chicago, St. Louis, Cincinnati—­and crossing the plains swifter than a prairie fire, making each peak of the Rocky Mountains hold up aloft a separate torch of flame, and the Sierras whiter with heat than they ever were with snow, the waters of the Pacific resolve into their constituent elements of oxygen and hydrogen, and [Page 78] burn with unquenchable fire!  We withdraw into the air, and see below a world on fire.  All the prisoned powers have burst into intensest activity.  Quiet breezes have become furious tempests.  Look around this flaming globe—­on fire above, below, around—­there is nothing but fire.  Let it roll beneath us till Boston comes round again.  No ember has yet cooled, no spire of flame has shortened, no surging cloud has been quieted.  Not only are the mountains still in flame, but other ranges burst up out of the seething sea.  There is no place of rest, no place not tossing with raging flame!  Yet all this is only a feeble figure of the great burning sun.  It is but the merest hint, a million times too insignificant.

The sun appears small and quiet to us because we are so far away.  Seen from the various planets, the relative size of the sun appears as in Fig. 30.  Looked for from some of the stars about us, the sun could not be seen at all.  Indeed, seen from the earth, it is not always the same size, because the distance is not always the same.  If we represent the size of the sun by one thousand on the 23d of September or 21st of March, it would be represented by nine hundred and sixty-seven on the 1st of July, and by one thousand and thirty-four on the 1st of January.

[Illustration:  Fig. 30.—­Relative Size of Sun as seen from Different Planets.]