"Twenty-nine thousand and two feet high, sir," he told them. "Highest mountain in the world. Cold as Christmas up at the top. Haven't been there myself, you know, but I'm guessing." "In fact, rather more uncomfortable there than down here," laughed the Major. "Well, Joe, it's a stumper?" "I cannot say. To cross above the highest peak we must ascend some five miles. That is a tremendous height; it will need special preparation." But one could see that Joe was bitten with the idea of accomplishing that which no other person or machine had ever achieved before. He went to the engine-room forthwith, and for the next two hours closely inspected the gasometer and carburettor which supplied his engines. Then he took the temperature of the crude paraffin which, unlike other internal-combustion motors, not only formed the explosive charge, and conveyed power through those long, sinuous, cold-drawn steel pipes to the distant hydraulic motors, but also surrounded the cylinders, acting as an effective cooling agent. If one had watched him one would have seen the thoughtful Joe working out some pleasant little calculations, calculations which would have given Dicky Hamshaw quite a headache. But the result seemed to satisfy him, for he once more inspected his engines, made a small adjustment, and then went off to the saloon. "Gentlemen," he said solemnly, "we have loaded our stores. If all are ready we will make for Mount Everest and there test the powers of this vessel." It was one of the many advantages of being aboard an airship. There was no packing to be done, no cabs to call, no trains to be entered. Joe had merely to return to the engine-room and start his motors, so that within ten minutes the ship was off, followed by the cheers and shrill native cries of thousands. For a while she hovered over the city of Delhi, mounting and mounting steadily, till she was but a speck in the sky, a speck almost invisible because of the material of which she was constructed. It was an object lesson to many thousands also. For where in all India, in all the world, was there a gun capable of reaching her, of destroying the airship, of preventing her crew, had they so wished, from dropping bombs upon the citizens of Delhi? "In war, an invincible arm," declared the Major with conviction. "A terrible arm, indeed, for here is a ship as secure, as handy, as manageable as any steamer. Let us hope that the report we shall take to War Office and Admiralty will not fall upon deaf ears. Or rather, let us pray that the authorities will test the truth of our statements by sending men aboard who are really qualified to form an opinion. Not amateurs, more or less filled with a sense of their own importance, and forgetful of that of others."