Read it through once

Now a number of the boats slide backward into the stream, leaving wide gaps in the serried rank of steamers. Citizens crowd the decks of boats that are not to go, in order to see the sight. Steamer after steamer straightens herself up, gathers all her strength, and presently comes swinging by, under a tremendous head of steam, with flag flying, black smoke rolling, and her entire crew of firemen and deck-hands (usually swarthy negroes) massed together on the forecastle, the best 'voice' in the lot towering from the midst (being mounted on the capstan), waving his hat or a flag, and all roaring a mighty chorus, while the parting cannons boom and the multitudinous spectators swing their hats and huzza! Steamer after steamer falls into line, and the stately procession goes winging its flight up the river.