As the one hundred and twenty pounds allowed for the four wings permitted only thirty pounds per wing, and as the cloth covering, lacing cords, etc., were found to weigh something over four pounds, there remained only about 25 pounds as the permissible weight of the wooden framing, including the necessary metal clips, secondary guy-wires, etc., for each wing. With the relative proportions of the various parts of the wooden framing of the wings of the models as a basis, it was decided to make the main ribs of the large wings 1.5 inches in diameter for one-half their length, and have them taper from this size to one inch in diameter at the extreme point. After making allowance for the weight of these ribs, it was found that, if the cross-ribs were to be spaced no farther than ten inches apart, and the two end ones were to be made at least as wide as 1.5 inches in order to resist the end strain due to the stress of the cloth, the twenty-six intermediate cross-ribs could be only seven-sixteenths of an inch in diameter at the point where they crossed the main rib, and that they must be tapered to three-eighths of an inch in diameter at the front end and to one-fourth of an inch in diameter at the rear tip. A trial wing, whose total weight was 30 pounds 2 ounces, was made up with the various parts of its frame of the above dimensions. Even upon inspection it appeared to be too flimsy to withstand the sudden gusts of wind which were certain to be met in actual practice. In order, however, to get some definite data as a guide, the wing was inverted and guyed in the same way that it was proposed to guy it on the aerodrome, and a uniform thickness of sand was then sprinkled over it to such a depth as to give it a load of 0.7 pounds per square foot. Even before one-quarter of the sand was sprinkled over it, it was seen that the wing was rapidly going out of shape, and it was feared that the full amount of sand would not only seriously distort it, but would even break it. The full quantity of sand, however, did not break it, but distorted it to such an extent that, had the pressure been due to its being propelled through the air, its serious change in form would have rendered it worse than useless. [p196] While the main ribs had shown a certain amount of deflection under the sanding test, the more serious distortion had been in the cross-ribs, the small guy-wires, which had been fastened to each cross-rib, becoming loose instead of tight, as had been expected, since the rib tended to increase its curvature instead of straightening out. This increase in the curvature of the cross-ribs was partly overcome by tying the guy-wire flat against the cross-rib for a distance of about 2 feet from the rear tip. But while this caused the guy-wire to tighten the general contour of the wing showed very little improvement, as the ribs now assumed a curve more or less like the letter S, the rear tip now being bent downward to form the tail of the elongated S.