时间: 2019年12月11日 07:40

She paused, silently looking at him for a moment. Then she drew nearer to him, and laid her arm round his shoulder. She wore a dinner-dress with loose hanging sleeves, which were not becoming to her wasted frame. But the poor thin arm clung with a loving touch to her husband, as she said, "I know I am not so clever as you, Ancram, but I can see and understand that if we haven't money enough to pay for things we must do without them." (Castalia advanced this in the tone of one stating a self-evident proposition.) "And I shan't care, Ancram, if you trust me, and鈥攁nd鈥攄on't put any one else before me. I never put any one before you. I was fond of Uncle Val. I think he was the only person I really loved in the world before I saw you. But if he treats you badly I shall give him up." [262] 鈥業t is a remarkable fact how this proportion of wing-surface to weight extends throughout a great variety of the flying portion of the animal kingdom, even down to hornets, bees, and other insects. In some instances, however, as in the gallinaceous tribe, including pheasants, this area is somewhat exceeded, but they are known to be very poor fliers. Residing as they do chiefly on the ground, their wings are only required for short distances, or for raising them or easing their descent from their roosting-places in forest trees, the shortness of their wings preventing them from taking extended flights. The wing-surface of the common swallow is rather more than in the ratio of two square feet per pound, but having also great length of pinion, it is both swift and enduring in its flight. When on a74 rapid course this bird is in the habit of furling its wings into a narrow compass. The greater extent of surface is probably needful for the continual variations of speed and instant stoppages for obtaining its insect food. Can I give any message for you to Mr. Errington, ma'am? There is, said he, a good Farm-House just by the Road near Kaxton; the honest Master of which, having, at some Market or Fair, received Money for Goods he had sold, was telling it over on Saturday Night, and put up in a Bag as much as would pay his Half-Year's Rent, telling his Man, That on Monday he should carry it to his Landlord; and, at the same Time, ordered his Labourer, (who was then receiving his Wages) to be sure to come early on Monday-Morning to take Care of the Yard, while his Man was out. There is one story of 1914 that must be included, however briefly, in any record of aeronautical achievement, since it demonstrates past question that to Professor Langley really belongs the honour of having achieved a design which would ensure actual flight, although the series of accidents which attended his experiments gave to the Wright Brothers the honour of first leaving the earth and descending without accident in a power-driven heavier-than-air machine. In March, 1914, Glenn Curtiss was invited to send a flying boat to Washington for the celebration of 鈥楲angley Day,鈥?when he remarked, 鈥業 would like to put the Langley aeroplane itself in the air.鈥?In consequence of this remark, Secretary Walcot of the Smithsonian Institution authorised Curtiss to re-canvas the original Langley aeroplane and launch it either under its own power or with a more recent engine and propeller. Curtiss completed this, and had the machine ready on the shores of Lake Keuka, Hammondsport, N.Y., by May. The main object of these renewed trials was to show whether the original Langley machine was capable of sustained free flight with a pilot, and a secondary object was to determine more fully the advantages of the tandem monoplane type; thus the aeroplane was first244 flown as nearly as possible in its original condition, and then with such modifications as seemed desirable. The only difference made for the first trials consisted in fitting floats with connecting trusses; the steel main frame, wings, rudders, engine, and propellers were substantially as they had been in 1903. The pilot had the same seat under the main frame and the same general system of control. He could raise or lower the craft by moving the rear rudder up and down; he could steer right or left by moving the vertical rudder. He had no ailerons nor wing-warping mechanism, but for lateral balance depended on the dihedral angle of the wings and upon suitable movements of his weight or of the vertical rudder. 天天摸日日碰人人看,人人摸人人草人人湿,天天爱天天看人人视频 CHAPTER VIII You鈥攜ou haven't seen him anywhere in the town? Two brothers, Albert and Gaston Tissandier, were338 next to enter the field of dirigible construction; they had experimented with balloons during the Franco-Prussian War, and had attempted to get into Paris by balloon during the siege, but it was not until 1882 that they produced their dirigible. In connection with stability mention must be made of a machine which was evolved in the utmost secrecy293 by Mr J. W. Dunne in a remote part of Scotland under subsidy from the War Office. This type, which was constructed in both monoplane and biplane form, showed that it was in fact possible in 1910 and 1911 to design an aeroplane which could definitely be left to fly itself in the air. One of the Dunne machines was, for example, flown from Farnborough to Salisbury Plain without any control other than the rudder being touched; and on another occasion it flew a complete circle with all controls locked, automatically assuming the correct bank for the radius of turn. The peculiar form of wing used, the camber of which varied from the root to the tip, gave rise, however, to a certain loss in efficiency, and there was also a difficulty in the pilot assuming adequate control when desired. Other machines designed to be stable鈥攕uch as the German Etrich and the British Weiss gliders and Handley-Page monoplanes鈥攚ere based on the analogy of a wing attached to a certain seed found in Nature (the 鈥榋anonia鈥?leaf), on the righting effect of back-sloped wings combined with upturned (or 鈥榥egative鈥? tips. Generally speaking, however, the machines of the 1909-1912 period relied for what automatic stability they had on the principle of the dihedral angle, or flat V, both longitudinally and laterally. Longitudinally this was obtained by setting the tail at a slightly smaller angle than the main planes. Certain records both in construction and performance had characterised the post-war years, though as design advances and comes nearer to perfection, it is obvious272 that records must get fewer and farther between. The record aeroplane as regards size at the time of its construction was the Tarrant triplane, which made its first鈥攁nd last鈥攆light on May 28th, 1919. The total loaded weight was 30 tons, and the machine was fitted with six 400 horse-power engines; almost immediately after the trial flight began, the machine pitched forward on its nose and was wrecked, causing fatal injuries to Captains Dunn and Rawlings, who were aboard the machine. A second accident of similar character was that which befell the giant seaplane known as the Felixstowe Fury, in a trial flight. This latter machine was intended to be flown to Australia, but was crashed over the water.