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Horatio Phillips' March 6, 1908 To the Editor of Engineering Sir - Having been very busy during the last six months, repeating and extending experiments I made may years ago, connected with the above subject, I omitted to mention one or two particulars respecting my machine, which may be of interest to your readers. The machine, including the horizontal rudder, is 15 ft. long, 20 ft. wide, and 10 ft. high. The sustainer blades in the frame next the propeller, or, rather, tractor, are set at a very fine angle, the blades in the second frame are set at a little coarser angle, and so on to the rear: this is done to accelerate the air in a downward direction, as it passes through each frame of blades. It is very important to arrange the angle of the blades so that the rear of the machine is the first to rise from the ground. The reason for placing the propeller or tractor in front is that the screw-race shall have its spirality eliminated by passing between the sustainer-blades and supporting-uprights, thus balancing the torsional effort on the shaft. The weight of the machine in working order, without driver, is 500 lb. The sustainer-blades, and frames which they are fitted, together weigh 8 oz. per square foot of under surface of blades, and the weight lifted by them in the 1893 trial was 3 lb. per square foot of the under surface, so that the proportion between the weight of the sustainers and the weight lifted was 6 to 1. ... My machine was designed for a forward speed of 50 ft. per second: the thrust, or pull, when standing is 220 lb; when running, say 200 lb. Now 200 X 50 = 10,000 ÷ 550 = 18 horse-power of the shaft. This result with a 20 to 22 horse-power engine would be considered by engineers highly efficient. Yours faithfully, Horatio
Phillips
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