Part 2 (1/2)
The croas larger than ever, and a the newcomers some of the most iitudinal, and Lateral, with their assistants, the Rudder, Elevator, and Ailerons
There was Centrifugal Force, too, ould not sit still and created a most unfavourable ile, and several other lesser fry
”Well,” said Centrifugal Force, ”I wish this Efficiency I've heard so ree withlike motion--the more the better”
”We are entirely opposed to that,” objected the three Stabilities, all in a breath ”Unless it's in a perfectly straight line or a perfect circle Nothing but perfectly straight lines or, upon occasion, perfect circles satisfy us, and we are strongly suspicious of your tendencies”
”Well, we shall see e shall see,” said the Force darkly ”But who in the name of blue sky is this?”
And in tripped Efficiency, in a beautifully ”doped” dress of the latest fashi+onable shade of khaki-coloured fabric, a perfectly strea little Morane parasol,[4] s, ”I'ner's such a funny man He objects to skin friction,[5] and insisted uponmy fabric for one of a smoother surface, and that delayed me
Dear me, there are a lot more of us to-day, aren't there? I think I had betterto Directional Stability, she politely asked him what he preferred to do
”My purpose in life, miss,” said he, ”is to keep the Aeroplane on its course, and to achieve that there must be, in effect,Axis than there is in front of it”
[Illustration]
Efficiency looking a little puzzled, he added: ”Just like a weathercock, and by Keel-Surface Iyou can see when you view the Aeroplane from the side of it--the sides of the body, struts, wires, etc”
”Oh, now I begin to see light,” said she; ”but just exactly how does it work?”
”I'll answer that,” said Moust of air the Aeroplane is blown out of its course and points in another direction, it doesn't i I pull it off the new course to a certain extent, and towards the direction of the old course And so it travels, as long as th lasts, in a more or less sideways position”
”Then,” said the Keel-Surface, ”I get a pressure of air all on one side, and as there is, in effect, ets pressed sideways, and the Aeroplane thus tends to assume its first position and course”
”I see,” said Efficiency, and, daintily holding the Chalk, she approached the Blackboard ”Is this what you h,” said the Keel-Surface, ”and you ht reusts rather than away from them”
”If that was not the case,” broke in Lateral Stability, and affecting the fashi+onable Flying Corps stammer, ”it would be a h-h-h-o-r-rible affair! If there were too ust would blow the Aeroplane round the other way a very considerable distance And the right-hand Surface being on the outside of the turn would have more speed, and consequently reater proportion of the Lift on that side, and before you could say Warp to the Ailerons over the Aeroplane would go--probable result a bad side-slip” (see illustration A, over-leaf)
”And what can the Pilot do to save such a situation as that?” said Efficiency
”Well,” replied Lateral Stability, ”he will try to turn the Aeroplane sideways and back to an even keel by ed on to the Wing-tips, and about which you will hear more later on; but if the side-slip is very bad he ht the Aeroplane byfor him to do is to use the Rudder and to turn the nose of the Aeroplane down and head-on to the direction ofthe air in the direction it is designed to do so, and the Surfaces and also the controls (the Rudder, Ailerons, and Elevator) will be working efficiently; but its attitude relative to the earth will probably bethe Aeroplane's nose down results, as you will see by the illustration B, in the right wing, which is on the outside of the circle, travelling through the air with greater speed than the left-hand wing More Speedthe Aeroplane stillthe air as it is designed toproperly It is then only necessary to warp the Elevator, as shown in illustration C, in order to bring the Aeroplane into a proper attitude relative to the earth”
[Illustration]
”Ah!” said the Rudder, looking wise, ”it's in a case like that when I become the Elevator and the Elevator becomes me”
”That's absurd nonsense,” said the Blackboard, ”due to looseness of thought and expression”
”Well,” replied the Rudder, ”when the Aeroplane is in position A and I am used, then I depress or _elevate_ the nose of the machine; and, if the Elevator is used, then it turns the Aeroplane to right or left, which is nored one with the other, and I'm then the Elevator and the Elevator is me!”
[Illustration]
Said Lateral Stability to the Rudder, ”That's altogether the wrong way of looking at it, though I admit”--and this rather sarcastically--”that the way you put it sounds rather fine when you are talking of your experiences in the air to those 'interested in aviation' but knowing little about it; but it won't go down here! You are a Controlling Surface designed to turn the Aeroplane about a certain axis of the ned to turn the Aeroplane about another axis Those are your respective jobs, and you can't possibly change them about Such talk only leads to confusion, and I hope we shall hear no more of it”
”Thanks,” said Efficiency to Lateral Stability ”And now, please, will you explain your duties?”