When the brothers set to work on their glider for the experiments of 1901, they decided to make it of the same general design as the first one, and with the same system of control. But they carried out their plan to give it considerably more area, to provide greater lifting power. Another change they made was to increase the curvature of the wings to conform to the shape on which Lilienthal had based his tables of air pressures. It had wings of about seven-foot chord (the straight line distance between the front and rear edges) with a total span of twenty-two feet, and weighed ninety-eight pounds. After a section twenty inches wide had been removed from the middle of the lower wing, and the rear corners of the wings rounded off, the total lifting area was 290 square feet, as compared with 165 in the previous glider. The front elevator, with its rear edge about two and one half feet away from the front edge of the wings, had a four-and-one-half foot chord and an area of eighteen square feet. This was a much larger machine than anyone had ever tried to fly. The Wrights knew it could not be controlled simply by shifting the pilot’s weight, as others had done, but they had faith in their own operable front elevator and believed they could manage it. If their calculations were correct, it would be supported in a wind of seventeen miles an hour, with the wing surfaces at an “angle of incidence” of only three degrees. (“Angle of incidence,” now more often called “angle of attack,” has been defined as the angle at which the plane presents itself to the air in advancing against it.) As it would be impractical to keep so large a machine with them in the tent, as they had done with the smaller glider, the brothers built near Kill Devil Hill a rough frame shed, twenty-five feet long, sixteen feet wide, and seven feet high at the eaves. Both ends of the building except the gable parts were made into doors, hinged above. When open, the doors provided an awning at each end of the building. For living quarters they still used a tent. By driving a pipe ten or twelve feet into the sand they got a water supply. Though the great stretch of sandy waste seemed too desolate for anyone to bother about owning, yet it was all under the ownership of one person or another and the Wrights took the precaution to obtain permission to erect their buildings.