Read it through once

What we saw there was simply a circular crater--a circular ditch, if you please--about two hundred feet deep, and four or five hundred feet wide, whose inner wall was about half a mile in circumference. In the centre of the great circus ring thus formed, was a torn and ragged upheaval a hundred feet high, all snowed over with a sulphur crust of many and many a brilliant and beautiful color, and the ditch inclosed this like the moat of a castle, or surrounded it as a little river does a little island, if the simile is better. The sulphur coating of that island was gaudy in the extreme--all mingled together in the richest confusion were red, blue, brown, black, yellow, white--I do not know that there was a color, or shade of a color, or combination of colors, unrepresented--and when the sun burst through the morning mists and fired this tinted magnificence, it topped imperial Vesuvius like a jeweled crown!