时间: 2019年12月06日 03:42

Practically all these vessels were discounted by the work of Ferdinand von Zeppelin, who set out from the first with the idea of constructing a rigid dirigible. Beginning in 1898, he built a balloon on an aluminium framework covered with linen and silk, and divided into interior compartments holding linen bags which were capable of containing nearly 400,000 cubic feet of hydrogen. The total length of this first Zeppelin airship was 420 feet and the diameter 38 feet. Two cars were rigidly attached to the envelope, each carrying a 16 horse-power motor, driving propellers which were rigidly connected to the aluminium framework of the balloon. Vertical and horizontal screws were used for lifting and forward driving and a sliding weight was used to raise or lower the stem of the vessel out of the horizontal in order to rise or descend without altering the load by loss of ballast or the lift by loss of gas. No matter: Caballo had already begun working on his plan. That鈥檚 the only reason he was in Creel. Why, you see, Mr. Errington, we are not in the habit of giving long credit, unless to a few old-established customers who deal largely with us. It would not suit our style of doing business. And it was reported that you were not settled permanently here. And鈥攁nd鈥攐ne or two unpleasant things had been said. But I hope you will not continue to feel so greatly offended with us for sending in the account. It was merely in the regular way of our transactions, I assure you. � 鈥淥ur whole approach to trail-running came from Dharma Bums,鈥?Billy told me later. As forinspiration, that鈥檚 where Charles Bukowski stepped up: 鈥淚f you鈥檙e going to try, go all the way,鈥?theoriginal Barfly wrote. 鈥淭here is no other feeling like that. / you will be alone with the gods / andthe nights will flame with fire鈥? you will ride life straight to / perfect laughter, it鈥檚 / the only goodfight there is.鈥? 鈥淪HUT UP!鈥?Billy screamed, so rattled by the sight of Jenn鈥檚 tears that he erupted in a total non-Bonehead frenzy. 鈥淛UST SHUT UP!鈥? 婷婷色香五月综合缴缴情_中国高清videossexotv_第九色区AV天堂 � The only point in this worthy of any note is the first device for maintaining stability automatically鈥擲wedenborg certainly scored a point there. For the rest, his theory was but theory, incapable of being put37 to practice鈥攈e does not appear to have made any attempt at advance beyond the mere suggestion. � Weasel. Much the same as usual, your honour. Our only varieties are Dr. Daresby and the rheumatics; till last night when.... These comments are taken from a lecture delivered by Wilbur Wright before the Western Society of Engineers in September of 1901, under the presidency of Octave Chanute. In that lecture Wilbur detailed the way in which he and his brother came to interest themselves in aeronautical problems and constructed their first glider. He speaks of his own notice of the death of Lilienthal in 1896, and of the way in which150 this fatality roused him to an active interest in aeronautical problems, which was stimulated by reading Professor Marey鈥檚 Animal Mechanism, not for the first time. 鈥楩rom this I was led to read more modern works, and as my brother soon became equally interested with myself, we soon passed from the reading to the thinking, and finally to the working stage. It seemed to us that the main reason why the problem had remained so long unsolved was that no one had been able to obtain any adequate practice. We figured that Lilienthal in five years of time had spent only about five hours in actual gliding through the air. The wonder was not that he had done so little, but that he had accomplished so much. It would not be considered at all safe for a bicycle rider to attempt to ride through a crowded city street after only five hours鈥?practice, spread out in bits of ten seconds each over a period of five years; yet Lilienthal with this brief practice was remarkably successful in meeting the fluctuations and eddies of wind-gusts. We thought that if some method could be found by which it would be possible to practise by the hour instead of by the second there would be hope of advancing the solution of a very difficult problem. It seemed feasible to do this by building a machine which would be sustained at a speed of eighteen miles per hour, and then finding a locality where winds of this velocity were common. With these conditions a rope attached to the machine to keep it from floating backward would answer very nearly the same purpose as a propeller driven by a motor, and it would be possible to practise by the hour, and without any serious danger, as it would not be necessary to rise far from the ground, and the machine would not have any forward motion151 at all. We found, according to the accepted tables of air pressure on curved surfaces, that a machine spreading 200 square feet of wing surface would be sufficient for our purpose, and that places would easily be found along the Atlantic coast where winds of sixteen to twenty-five miles were not at all uncommon. When the winds were low it was our plan to glide from the tops of sandhills, and when they were sufficiently strong to use a rope for our motor and fly over one spot. Our next work was to draw up the plans for a suitable machine. After much study we finally concluded that tails were a source of trouble rather than of assistance, and therefore we decided to dispense with them altogether. It seemed reasonable that if the body of the operator could be placed in a horizontal position instead of the upright, as in the machines of Lilienthal, Pilcher, and Chanute, the wind resistance could be very materially reduced, since only one square foot instead of five would be exposed. As a full half horse-power would be saved by this change, we arranged to try at least the horizontal position. Then the method of control used by Lilienthal, which consisted in shifting the body, did not seem quite as quick or effective as the case required; so, after long study, we contrived a system consisting of two large surfaces on the Chanute double-deck plan, and a smaller surface placed a short distance in front of the main surfaces in such a position that the action of the wind upon it would counterbalance the effect of the travel of the centre of pressure on the main surfaces. Thus changes in the direction and velocity of the wind would have little disturbing effect, and the operator would be required to attend only to the steering of the machine, which was to be effected152 by curving the forward surface up or down. The lateral equilibrium and the steering to right or left was to be attained by a peculiar torsion of the main surfaces, which was equivalent to presenting one end of the wings at a greater angle than the other. In the main frame a few changes were also made in the details of construction and trussing employed by Mr Chanute. The most important of these were: (1) The moving of the forward main crosspiece of the frame to the extreme front edge; (2) the encasing in the cloth of all crosspieces and ribs of the surfaces; (3) a rearrangement of the wires used in trussing the two surfaces together, which rendered it possible to tighten all the wires by simply shortening two of them.鈥?