“A subterranean river, I reckon,” responded Silas, “an’ one with a fairish slope, judgin’ by the speed we’re travellin’ at.” “I have no doubt,” Mervyn began, “that this strange tunnel is of volcanic origin; at one time probably a lava passage, through which the molten metal was forced from the bowels of the earth to the crater of the volcano we have left far behind us.” “If that is true,” interrupted Seymour, “we are plunging each instant deeper and deeper into the bowels of the globe, and at the present moment must be far down below the bed of the Polar Sea!” “Exactly!” returned Mervyn. “We started upon this trip as a North Polar expedition, but it seems we are to end up with a journey to the centre of the earth. Whether we ever return therefrom depends wholly upon Providence.” “Then where shall we end up?” the inventor asked, his face a picture of incredulous amazement. “I mean, what is there below?” “Heaven alone knows,” the scientist returned gravely; “yet, as we have been delivered in so marvellous a manner from the grip of the magnetic mountain, we will hope for the best.” “I guess we’ve just got to sit tight and see it through,” cried the Yankee. “Without her screws the old boat’s as helpless as a log, though I doubt if they’d ha’ been any use against this darned current. I calculate that feed you was preparin’ would be acceptable at the present period, Garth.” Taking the hint conveyed in the last sentence, the inventor withdrew, and soon from below came the rattle of crockery and the clatter of knives and forks. The walls of the tunnel still flashed by in an eternal monotony, and long, pendant mosses, trailing their slimy lengths from the rocky roof, seemed to writhe and twist like dark green snakes as the vessel swept past beneath them. And with every yard of her advance--and this was the thought that haunted her crew--the _Seal_ plunged deeper into the unknown depths of the earth! Her pace became terrific as the time went by, and the eyes of the watchers in her turret were strained ahead, expecting--yet dreading--each moment that some fearful abyss would yawn before them, in the black depths of which their faithful vessel would be swallowed up. Steering was utterly out of the question, even had the vessel not been damaged; for so great was the speed, that no sooner had they sighted a dangerous curve in the tunnel, of an out-jutting rock, than the _Seal_ was upon it. The swiftness of the current alone prevented the submarine from shattering herself to fragments against the numerous obstacles. Glad were the party when Garth’s voice summoned them below, and, leaving the vessel to take care of herself, they retired, to forget for a while the danger of their novel position in the pleasures of the table.