While the results obtained with superposed wings in the tests of models Nos. 5 and 6 in the summer of 1899 indicated that the “single-tier” surfaces were much more efficient, still, as has been already stated, the great advantages of the superposed surfaces, so far as strength of construction is concerned, was fully realized at all times. As a result of these tests it was decided to use the “single-tier” surfaces in the first test of the large machine in order to insure as far as possible the best conditions. However, it was from the beginning planned to construct superposed surfaces for use in the later tests of the large machine; and, in order to obtain more reliable data on such surfaces than had been obtained in the tests of the models in the summer of 1899, a set of superposed surfaces for the quarter-size model were constructed during the winter of 1900–1901. The quarter-size model, equipped with these surfaces, is shown in Plates 75 and 76, where the model is seen mounted on its launching car, which is attached to the floats heretofore referred to. It was originally planned not to employ guy-posts when using the superposed surfaces, but after the latter had been constructed and attached to the frame, it was found that they would have to be made with rigid joints instead of hinged joints if the guy-posts were omitted. As the hinged joints, however, were already made, and permitted the surfaces to be folded up so as to occupy a much smaller [p232] space in shipping them, it was decided to retain the hinged form of construction and use the guy-posts as shown in the above plates. [Illustration: PL. 70 PLAN VIEW OF QUARTER-SIZE MODEL AERODROME, JUNE 1, 1900] [Illustration: PL. 71 PLAN VIEW OF QUARTER-SIZE MODEL AERODROME] [Illustration: PL. 72 END, SIDE, AND THREE-QUARTER ELEVATION OF QUARTER-SIZE MODEL AERODROME] [Illustration: PL. 73 LAUNCHING-CAR WITH FLOATS] [Illustration: PL. 74 LAUNCHING-CAR WITH FLOATS] [Illustration: PL. 75 QUARTER-SIZE MODEL AERODROME EQUIPPED WITH SUPERPOSED SURFACES, JUNE 11, 1901, SIDE VIEW] [Illustration: PL. 76 QUARTER-SIZE MODEL AERODROME EQUIPPED WITH SUPERPOSED SURFACES, JUNE 11, 1901. END VIEW] [Illustration: PL. 77 CYLINDERS OF ENGINE OF QUARTER-SIZE MODEL AERODROME]