The steamer Silveropolis was sharply and steadily cleaving the broad, placid shallows of the Sacramento River. A large wave like an eagre, diverging from its bow, was extending to either bank, swamping the tules and threatening to submerge the lower levees. The great boat itself-a vast but delicate structure of airy stories, hanging galleries, fragile colonnades, gilded cornices, and resplendent frescoes-was throbbing throughout its whole perilous length with the pulse of high pressure and the strong monotonous beat of a powerful piston. Floods of foam pouring from the high paddle-boxes on either side and reuniting in the wake of the boat left behind a track of dazzling whiteness, over which trailed two dense black banners flung from its lofty smokestacks.