>

免费看成年人视频大全_免费看成年人视频在线观看_第一改装网

时间: 2019年12月14日 10:20

� � � In the spring of 1897 Pilcher took up his gliding experiments again, obtaining what was probably the best of his glides on June 19th, when he alighted after a perfectly balanced glide of over 250 yards in length, having crossed a valley at a considerable height. From his various experiments he concluded that once the machine was launched in the air an engine of, at most, 3 horse-power would suffice for the maintenance of horizontal flight, but he had to allow for the additional weight of the engine and propeller, and taking into account the comparative inefficiency of the propeller, he planned for an engine of 4 horse-power. Engine and propeller together were estimated at under 44 lbs. weight, the engine was to be fitted in front of the operator, and by means of an overhead shaft was to operate the propeller situated in rear of the wings. 1898 went by while this engine was under construction. Then in 1899 Pilcher became interested in Lawrence Hargrave鈥檚 soaring kites, with which he carried out experiments during the summer of 1899. It is believed that he intended to incorporate a number of these kites in a new machine, a triplane, of which the fragments remaining are hardly sufficient to reconstitute the complete glider. This new machine was never given a trial, for on September 30th, 1899,106 at Stamford Hall, Market Harborough, Pilcher agreed to give a demonstration of gliding flight, but owing to the unfavourable weather he decided to postpone the trial of the new machine and to experiment with the 鈥楬awk,鈥?which was intended to rise from a level field, towed by a line passing over a tackle drawn by two horses. At the first trial the machine rose easily, but the tow-line snapped when it was well clear of the ground, and the glider descended, weighed down through being sodden with rain. Pilcher resolved on a second trial, in which the glider again rose easily to about thirty feet, when one of the guy wires of the tail broke, and the tail collapsed; the machine fell to the ground, turning over, and Pilcher was unconscious when he was freed from the wreckage. The whole city of Berlin was agitated by the rumor of these events. The violent scene in the palace had taken place in an apartment on the ground floor. The loud and angry tones of the king, the shrieks of the queen, the cries of the children, the general clamor, had so attracted the attention of the passers-by that a large crowd had assembled before the windows. It was necessary to call out the guard to disperse them. Difficult as it was to exaggerate outrages so infamous, still they were exaggerated. The report went to all foreign courts that the king, in his ungovernable rage, had knocked down the Princess Wilhelmina and trampled her to death beneath his feet. 304 Early in 1914 it became known that the experimental work of Edward Busk鈥攚ho was so lamentably killed during an experimental flight later in the year鈥攆ollowing upon the researches of Bairstow and others had resulted in the production at the Royal Aircraft Factory at Farnborough of a truly automatically stable aeroplane. This was the 鈥楻.E.鈥?(Reconnaissance Experimental), a development of the B.E. which has already been referred to. The remarkable feature of this design was that there was no particular device to which one could point out as the cause of the stability. The stable result was attained simply by detailed design of each part of the aeroplane, with due regard to its relation to, and effect on, other parts in the air. Weights and areas were so nicely arranged that under practically any conditions the machine tended to right itself. It did not, therefore, claim to be a machine which it was impossible to upset, but one which if left to itself would tend to right itself from whatever direction a gust might come. When the principles were extended to the 鈥楤.E. 2c鈥?type (largely used at the outbreak of the War) the latter machine, if the engine were switched off at a height of not less than 1,000 feet above the ground, would after a few moments assume its correct gliding angle and glide down to the ground. 免费看成年人视频大全_免费看成年人视频在线观看_第一改装网 Ignition of the engine is by means of two Bosch Z H 6 magnetos, driven at a speed of 2,175 revolutions per minute when the engine is running at its normal speed of 1,450 revolutions. The maximum advance465 of spark is 12 mm., or 32 degrees before the top dead centre, and the firing order of the cylinders is 1, 5, 3, 6, 2, 4. � � Made you a present of an old coat and breeches! What on earth do you mean? These potential assets do not take into consideration the fact that efficiency is required not only in rising, landing, and remaining stationary in the air, but also in actual flight. It must be evident that if a certain amount of the motive force is used in maintaining the machine off the ground, that amount of force is missing from the total of horizontal driving power. Again, it is often assumed by advocates of this form of flight that the rapidity of climb of the helicopter would be far greater than that of the driven plane; this view overlooks the fact that the maintenance of aerodynamic support would claim the greater part of the engine-power; the rate of ascent would be governed by the amount of power that could be developed surplus to that required for maintenance.