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时间: 2019年12月11日 02:25

� Mrs. Errington, I don't know whether you are feigning or not. But, anyway, I think it my duty to answer you with Christian sincerity. It is borne in upon me that I ought to do so. "Forgive me," she said angelically, "and let's change the subject. Come into the library, and I'll order tea." � Thou hast recalled a name! He drew a little nearer to her as he asked the question, and looked at the book she held. 日本高清视频网站www_日本高清视频在线观看_日本高清视频在线网站 62 Under these circumstances, it is proposed to raise an immediate sum of 锟?,000 in furtherance of the Projector鈥檚 views, and as some protection to the parties who may embark in the matter, that this is not a visionary plan for objects imperfectly considered, Mr Colombine, to whom the secret has been confided, has allowed his name to be used on the occasion, and who will if referred to corroborate this statement, and convince any inquirer of the reasonable prospects of large pecuniary results following the development of the Invention. I say, cried Maxfield, addressing the rest of the company, and entirely ignoring the rash delinquent Gibbs, "that these things are a snare and a delusion, and the work of the devil. And when them of more wisdom and experience than me comes forward to speak on the matter, I shall be glad to show forth my reasons." The rosebuds that bloom on thy fat little cheek,鈥? "Listen, Bobo," said Jack crisply. "You've got to stay in bed to-day. I've hidden all your clothes. I've engaged a nurse to look after you鈥攁nd she'll see that you get your meals. You'd best take it quietly, for I'm giving it out that you've been on a tear, and if you make a racket people will think it's the D.T.'s." 鈥楾he act of flying requires less exertion than from the appearance is supposed. Not having sufficient data to ascertain the exact degree of propelling power exerted by birds in the act of flying, it is uncertain what degree of energy may be required in this respect for vessels of aerial navigation; yet when we consider the many hundreds of miles of continued flight exerted by birds of passage, the idea of its being only a small effort is greatly corroborated. To apply the power of the first mover to the greatest advantage in producing this effect is a very material point. The mode universally adopted by Nature is the oblique waft of the wing. We have only to choose between the direct beat overtaking the velocity of the current, like the oar of a boat, or one applied like the wing, in some assigned degree of obliquity to it. Suppose 35 feet per second to be the velocity of an aerial vehicle, the oar must be moved with this speed previous to its being able to receive any resistance; then if it be only required to obtain a pressure of one-tenth of a lb. upon each square foot it must exceed the velocity of the current 7.3 feet per second. Hence its whole velocity must be 42.5 feet per second. Should the same surface be wafted downward like a wing with the hinder edge inclined upward in an angle of about 50 deg. 40 feet to the current it will overtake it at a velocity of 3.5 feet per second; and as a slight unknown angle of resistance generates a lb. pressure per square foot at this velocity, probably a waft of a little more than 4 feet per second would produce this effect, one-tenth part of which would be the propelling power. The advantage of this mode of48 application compared with the former is rather more than ten to one.