John kept the machine mounting at a good angle until the altimeter showed them to be up two thousand feet.  Then he straightened out the ailerons and elevators, and began to run on a level keel.  The other inmates of the cabin noticed, by looking through the observation windows, that he was gradually bearing in a great circle about the town of Yonkers.  Off to the northwestward were the rugged blue crags of the Catskills, covered with patches of milk-white snow, and just in front, winding like a huge serpent among the picturesque foothills, was the sparkling Hudson, dwindling away to a mere silver thread in the north, tapering away in the same manner toward the south, where it lapped the piers of the city of New York and immediately afterward lost itself in the waters of the Upper Bay.  Although the great skyscrapers of the big city itself could be dimly seen, they looked very small at that distance.