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Aviation History
1910
1910 - 0070.PDF
1/ycRf] AN AERIAL PADDLE. [3°5l Knowing the great interest taken by a great many of your readers in propellers, I venture to submit a new form of propeller I have lately protected. As you will see by the photo, it was tested by mounting a pair on a cycle and driving them from the back wheel by a chain. The machine and rider weighed 200 lbs., and could be moved from a standing position, working the propellers by manual power up to a speed of about 80 r. p.m. As wood was used for the bearings there was considerable loss in friction, also, there is no doubt, the timing of the blades to open WMmmammmmmmum and close could be improved on. I claim for this propeller a greater thrust per h. p. than the screw propeller now used ; it is reasonable to suppose the efficiency of the dirigible balloon would be greatly increased if such propellers were fitted, as they run at a lower speed and would require less h.p. I should be pleased to demonstrate them to you, or any of your readers feeling interested, by appointment. Highgate Road. E. SIMKINS. [The device srwwn in the accompanying photograph would be better described as a feathering paddle. An ordinary paddle is, of course, useless for aerial work because, being submerged in the fluid in which it acts, its propulsive effect is equal in both directions. Paddles for marine propulsion drive a boat by virtue of the difference in density between the water and the air.—ED.] FLIGHT GOLF. [306] I notice a letter from A. E. Jones in your current issue, forwarded to me, in reference to " Flight Golf." I think there is the germ of quite a good idea in it, but to be practicable the only similarity to golf would be the fact that the scoring would be by the numb-r of flights required to reach a certain spot ; it would not be advisable to have more than about six " holes " or points of destination, otherwise it would take an endless time to play a game. The " holes "—or perhaps we might call them "greens"—ought to be as much in the form of a triangle as possible, so as to be the same for most changes of wind, and might be the size for average golf green. Some form of mechanical winding would be necessary, of course, to save time, and I should think quite a small model would be better than a large one. The great difficulty would be strong winds. No doubt, given suitable weather, such a game would be very educative, as at present most of us are content to get a good flight in any direction, and do not bother to find out the best way of reaching a given spot sideways or against the wind. Two propellers are a great help to continuity of direction provided they run at the same JANUARY 22, 1910. speed, or it is easily possible by winding the leeward one a few more turns to make my own model fly straight across a wind. Gliding over Snow.—To change the subject, up here on the snow-covered Swiss mountains, would be a most excellent place to learn gliding. There is seldom any wind, slopes in abundance of every gradient, a pair of skis fitted to the plane would form a perfect means for gaining momentum, and the landing would be soft and easy. Of course in a wind it might be difficult, as the currents must be very complicated. Montana s. Sierre (Switzerland). FLEMING WILLIAMS. ANTOINETTE MODEL. r3°7] I, in conjunction with my brother, Mr. Walter Edward Fox, am constructing a large motor-driven Antoinette model, and would be glad if you could furnish us with a few particulars of the full size machine which are not fully explained in your description of the latter. We desire to make as near a copy of the original flyer as possible. Query 1.—Do the main spars enter the fusellage vertically or do they tilt according to the angle of incidence ? Query 2.—Can you kindly oblige us with a sketch of the bracket which fastens the leading spar to the body of the machine, and another explaining the chassis, and whether the ash skid projecting from the front of the flyer is fixed at its top end to the narcelle or to the vertical steel tube of the landing arrangement ? Query 3.—Is the cross-piece which supports the main bracing spar composed of metal or wood ? Query 4.—What is the dihedral angle of the wings to the horizontal ? Query 5.— Are the warping wires connected to the wings at the junction of the vertical strut with the main spar or nearer the tips ? Query 6.—Is the greatest depth of the fusellage greater than the greatest width. And what are the exact measurements ? Query 7.—How far is the trailing edge of the main planes (at then- greatest width) below the leading edge ? Query 8.—In what way are the rudders hinged to the tail planes? Query 9.—Is the keel of the body, at the point where the chassis joins it, composed of a single member or two, spaced a few inches apart ? (This is suggested by the fact that the centre bracing strut is a continuation of the vertical hollow steel tube of the shock- absorbing contrivance.) If possible, we intend to exhibit the machine at the forthcoming Olympia " Aero " Show next March. Thanking the proprietors of FLIGHT for making their journal suck an interesting and instructive paper. Chiswick, W. ERNEST WARDE FOX. [1. Spars tilt. 2. Similar to rear spar attachment, but without pivot. 3. Wood. 4. Unknown. 5. At the junction as shown ALUMINIUM FERRULE.S TAIL POST f HINC;E. DETAIL. on p. 663. 6. Exact figures unknown ; scale off from p. 663. 7. Unknown. 8. Hinges for both elevator and rudder formed of brass wire eyes as in accompanying sketch. 9. A wooden yoke is provided surrounding the pillar.—ED.] 66 FORMULAE. [308] In reply to letter No. 282 of Mr. J. D. Ross, some of the points he raises are dealt with fully in a book which I have in the press, and which is to be sold at a figure below 10s. I do not think there is anything quite at the low price your correspondent mentions which would give him the information. With regard to Question 3, as to ratio between surface area of the propeller blades and that of the aerofoils, it does not appear to me that any useful purpose would be served by a formula for this, as no definite relation exists. So much depends on other ruling factors, and the propeller problem in
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