登陆注册
14828100000025

第25章

It is a mistaken idea that flying machines must be operated at extreme altitudes. True, under the impetus of handsome prizes, and the incentive to advance scientific knowledge, professional aviators have ascended to considerable heights, flights at from 500 to 1,500 feet being now common with such experts as Farman, Bleriot, Latham, Paulhan, Wright and Curtiss. The altitude record at this time is about 4,165 feet, held by Paulhan.

One of the instructions given by experienced aviators to pupils, and for which they insist upon implicit obeyance, is:

"If your machine gets more than 30 feet high, or comes closer to the ground than 6 feet, descend at once." Such men as Wright and Curtiss will not tolerate a violation of this rule. If their instructions are not strictly complied with they decline to give the offender further lessons.

Why This Rule Prevails.

There is good reason for this precaution. The higher the altitude the more rarefied (thinner) becomes the air, and the less sustaining power it has. Consequently the more difficult it becomes to keep in suspension a given weight. When sailing within 30 feet of the ground sustentation is comparatively easy and, should a fall occur, the results are not likely to be serious. On the other hand, sailing too near the ground is almost as objectionable in many ways as getting up too high. If the craft is navigated too close to the ground trees, shrubs, fences and other obstructions are liable to be encountered.

There is also the handicap of contrary air currents diverted by the obstructions referred to, and which will be explained more fully further on.

How to Make a Start.

Taking it for granted that the beginner has familiarized himself with the manipulation of the machine, and especially the control mechanism, the next thing in order is an actual flight. It is probable that his machine will be equipped with a wheeled alighting gear, as the skids used by the Wrights necessitate the use of a special starting track. In this respect the wheeled machine is much easier to handle so far as novices are concerned as it may be easily rolled to the trial grounds. This, as in the case of the initial experiments, should be a clear, reasonably level place, free from trees, fences, rocks and similar obstructions with which there may be danger of colliding.

The beginner will need the assistance of three men.

One of these should take his position in the rear of the machine, and one at each end. On reaching the trial ground the aviator takes his seat in the machine and, while the men at the ends hold it steady the one in the rear assists in retaining it until the operator is ready. In the meantime the aviator has started his motor. Like the glider the flying machine, in order to accomplish the desired results, should be headed into the wind.

When the Machine Rises.

Under the impulse of the pushing movement, and assisted by the motor action, the machine will gradually rise from the ground--provided it has been properly proportioned and put together, and everything is in working order. This is the time when the aviator requires a cool head, At a modest distance from the ground use the control lever to bring the machine on a horizontal level and overcome the tendency to rise. The exact manipulation of this lever depends upon the method of control adopted, and with this the aviator is supposed to have thoroughly familiarized himself as previously advised in Chapter XI.

It is at this juncture that the operator must act promptly, but with the perfect composure begotten of confidence. One of the great drawbacks in aviation by novices is the tendency to become rattled, and this is much more prevalent than one might suppose, even among men who, under other conditions, are cool and confident in their actions.

There is something in the sensation of being suddenly lifted from the ground, and suspended in the air that is disconcerting at the start, but this will soon wear off if the experimenter will keep cool. A few successful flights no matter how short they may be, will put a lot of confidence into him.

Make Your Flights Short.

Be modest in your initial flights. Don't attempt to match the records of experienced men who have devoted years to mastering the details of aviation. Paulhan, Farman, Bleriot, Wright, Curtiss, and all the rest of them began, and practiced for years, in the manner here described, being content to make just a little advancement at each attempt. A flight of 150 feet, cleanly and safely made, is better as a beginning than one of 400yards full of bungling mishaps.

And yet these latter have their uses, provided the operator is of a discerning mind and can take advantage of them as object lessons. But, it is not well to invite them. They will occur frequently enough under the most favorable conditions, and it is best to have them come later when the feeling of trepidation and uncertainty as to what to do has worn off.

同类推荐
热门推荐
  • 俏皮可爱的紫貂:哺乳动物

    俏皮可爱的紫貂:哺乳动物

    哺乳动物不但聪明绝顶,而且身怀绝技,由它们统治着整个世界,是自然界的选择。想必你一定很好奇,哺乳动物的聪明表现在什么地方,它们又有哪些独门绝技呢?它们又是如何统治地球的呢?现在,就让我们带着这些疑问,翻开《青少年科普图书馆·俏皮可爱的紫貂:哺乳动物》一起走进哺乳动物神奇的世界吧!《俏皮可爱的紫貂:哺乳动物》内容简介:无论是身怀绝技的动物,还是形态各异的植物,抑或是我们生活中见所未见、闻所未闻的神秘生物,它们共同构成一个光怪陆离的生物世界。“图说生物世界”将为你展现生物世界的趣味,描绘生物世界的新奇,揭开生物世界的神秘。
  • 情帝

    情帝

    末日般的璀璨,从他手中绽放之时,举世方才明白,情绪的终极力量究竟为何。这是一个平凡卑微的人,在不平凡的千世累积后,重生到异世,驾驭情绪之力,成为万世仰望的传奇,情绪是一种力量!(愤怒;喜乐;忧思;悲哀;恐惧。)
  • 亡灵召唤使

    亡灵召唤使

    沈建已经72小时没合眼了,因为他身边围着一群鬼魂。而这些鬼魂,竟然是一个面目可憎的糟老头派来的。魍魉之气笼罩整个城市,一场天大的浩劫,正压城而来……
  • 异能者:腹黑公主闯天下

    异能者:腹黑公主闯天下

    她,是皇室中最小的公主,天性好动贪玩,为了逃避父皇的追捕来到了人才济济的异能学院……
  • 兵之奇缘

    兵之奇缘

    在故事里没有很火爆的军旅场面,也没有英雄的出现,更没有什么特种兵的故事,有的只是一个女孩子与两个军人的简单的爱情故事。一个陪着她走过了年少时光,一个给她了安稳幸福的生活。。。。。
  • 翼封

    翼封

    2050年,设身处地由数据虚拟构成类似三次元游戏,VRMMO诞生了。风靡全世界,千万玩家投入其中排行榜第一的TFC中,一代天骄横空出世。轻松通关让无数玩家无能为力的关卡,惊为天人少年之姿参加终极玩家PK赛,在百万玩家中脱颖。那不同常人的异瞳闪烁千万玩家的眼,迷失多少少女的心谁能想到,那一己之力单撼第一公会威压的少年,竟是…她墨发飘扬,红裾翻飞。拥有独立道具【双面】的她,为了一个代表她所亲密之人性命的惊天赌注,睥睨一众崇拜,傲然斩下一切。现实中她则凭病秧子的身体,斩关破将,拼尽超常人游戏能力杀入全国比赛。荣耀的勋章,会成为她救赎的证明。将会着一身血艳金袍,傲然立于这世界之巅,向天下展示绝代风华!
  • 九曲莲花

    九曲莲花

    在山头长出了罕见的莲花,一时间三大派为了得到莲花斗智斗勇,最后却扯出来了一桩事情,原来都是设的局。
  • TFBOYS之雨墨初晴,夜

    TFBOYS之雨墨初晴,夜

    袁筱冉,一个普通女孩,因为在考上的清华大学结交了一个叫易烊千玺的少年,他们处的蛮不错的,因为一次机会,易烊千玺把自己的朋友介绍给筱冉,一次一次,他们的友情渐渐变得不一般了,就好像亲人一样。而因为TFBOYS因为考大学时决定隐退,可就在王俊凯大三时准备复出,这让筱冉一定措手不及,不知如何是好,毕竟如果他们再次在娱乐圈里面混那必当把他们的距离拉远,这该如何是好呢?她究竟会怎么样选择当时的局面呢?
  • 逆天之谁敢争锋

    逆天之谁敢争锋

    修行世界,强者无数!但,能够有实力行走在无尽岁月中的人,却不多……林进,本是一名研究历史的学者,无意中在一本家传的古书上,发现了一个秘密。那是一本家族中的禁书,漆黑的封皮包裹着厚厚的纸卷,书面上用红色的颜料写下了一行小字:吾辈后人,不可打开;其内,封有妖!
  • 我最想要的投资学速读本

    我最想要的投资学速读本

    你不理财,财不理你不论贫富,投资理财都是伴随人生的大事,在这场“人生经营”过程中,愈穷的人愈要积极行动,越是没钱的人越需要投资理财。通过不断的投资积累,改变自己的人生。投资学研究如何在股票、国债、不动产等(金融)资产上合理分配个人,机构的有限资源,以获得合理的现金流量和风险/收益率。其核心就是以效用最大化准则为指导,获得个人财富配置的最优均衡解。不论贫富,投资理财都是伴随人生的大事,在这场“人生经营”过程中,愈穷的人愈要积极行动,越是没钱的人越需要投资理财。通过不断的投资积累,改变自己的人生。