Of course they were all trusted scientists, men on whose word reliance was placed, but it seems to be a trait in human nature to doubt anything abnormally wonderful, unusual, or even contrary to established belief and expectations; and though the weight of numbers all telling the same story precluded avowed incredulity, all knew that to state such startling and unexpected facts without substantial and indisputable proof would but cause people to disbelieve at heart while apparently agreeing with what they could not deny. They could only leave it to chance to provide them the evidence required, so they dismissed the matter for the moment, and several suggested that they should rise and examine the interior of the crust, or shell. Accordingly Dennis caused the _Regina_ to rise till her dome was just below the crust, but near as were the lights, their powerful beams failed to penetrate the gas, rendered thick by the fine dust which absorbed their rays. The vessel then circled the crust, travelling immediately beneath, but though many samples of air were taken, the same results followed, revealing only nitrogen. After the circuit had been made, Ross inquired, “Are we going upward outside, the way we came, or shall we descend to the centre?” Some were for returning and others for sinking, when Sorrel said: “Let us fall, Ainley. There’s no telling what will happen, and as we _are_ here we shall see, at any rate, if the whole of the interior is nitrogen.” This now meeting with general assent, the ship fell steadily, all the search-lights full on, and every face was pressed closely to the windows, watching the opaque wall of dust, so that no alteration or passing object should escape notice. In a few minutes there was a general exclamation of surprise, as, simultaneously, all saw a change take place in the fog around, and there was a sudden cry from various places, “Oxygen, with nitrogen—nitrogen peroxide!” Instantly the ship was stopped, and on all sides the wall of fog showed ruddy-coloured and glowing. The particles of dust were being destroyed, either by heat or evaporation, for the light now penetrated several feet and the haze had the distinct red glow which comes from the chemical combination of nitrogen with oxygen, though on Earth such a union is caused by the action of intense heat. Again was there great excitement, and all crowded round Gilbert, as he obtained and examined a sample of the outer air, which but confirmed their suppositions, there being a perceptible diminution in the quantity of dust collected. It was now about the usual time for retiring to rest but all ignored the automatic electric signal; sleep, even rest, was out of the question, for who could sleep when such strange and marvellous phenomena were unfolded before them in such unexpected and exciting form.