One tentative assumption of Mattullath’s, made on the authority of Maxim and Langley, was that the friction of the air is a negligible part of the entire resistance encountered by the hull, framing and sail surfaces. Accepting their experimental conclusion, he designed a flyer so sharp and smooth in all its parts as practically to eliminate the pressural, or head resistance. With no skin friction, with scant hull and frame resistance, he could afford[41] to fly at a very slight angle, thus minimizing the drift, or wing resistance, while at the same time securing abundant lift by rapidity of flight. He thus arrived, by cold deduction from the data of those prominent experimentalists, at an aëroplane swift as the albatross, and wondrously economical of power. But his financiers were loath to gamble on that assumption. He therefore, at their suggestion, instigated systematic measurements of air friction on smooth surfaces, which demonstrated that in a sharp aëroplane flying at a very slight angle, the skin friction is nearly equal to all the other resistances combined. These results were obtained and published[42] some months after his death. They were unfavorable to his project, and to all projects for attaining high speed through the air by excessive sharpening of the vehicle. The first dynamic aëroplane of adequate stability and power to carry a man in prolonged flight, was that of Professor Langley. This machine was nearly a duplicate, on a four-fold scale, of the gasoline model previously described, which had flown many times with good inherent equilibrium. There was accordingly every reason to expect that, weighted and launched like the model, it would fly with the same poise and swiftness, even if left to govern itself. Having in addition a living pilot, provided with rudders for steering and balancing, together with adequate fuel for a long journey, it seemed to promise still better results than the model. But an unfortunate accident in the launching so crippled this carefully designed craft that it fell down helpless, without a chance to exhibit its powers of sustentation and balance, even for a moment, in normal flight.