The Aeroplane Speaks [5]
power, it will lift vertically, but having regard to the mechanical difficulties of such construction, it is a most inefficient way of securing lift compared with the arrangement of an inclined surface driven by a propeller revolving about a horizontal axis.
``Then, if the Pilot is green, my chance will come,'' said the Maximum Angle of Incidence. ``For if the Angle is increased over the Best Climbing Angle, the Drift will rush up; and the Speed, and with it the Lift, will, when my Angle is reached, drop to a point when the latter will be no more than the Weight. The Margin of Lift will have entirely disappeared, and there we shall be, staggering along at my tremendous angle, and only just maintaining horizontal flight.''
``And then with luck I'll get my chance,'' said the Drift. ``If he is a bit worse than green, he'll perhaps still further increase the Angle. Then the Drift, largely increasing, the Speed, and consequently the Lift, will become still less, i.e., less than the Weight, and then--what price pancakes,[[3]] eh?''
[[3]] Pancakes: Pilot's slang for stalling an aeroplane and dropping like a pancake.
``Thank you,'' from Efficiency, ``that was all most informing. And now will you tell me, please, how the greatest Speed may be secured?''
``Certainly, now it's my turn,'' piped the Minimum Angle of Incidence. ``By means of the Elevator, the Pilot places the Aeroplane at my small Angle, at which the Lift only just equals the Weight, and, also, at which we shall make greater speed with no more Drift than before. Then we get our greatest Speed, just maintaining horizontal flight.''
``Yes; though I'm out of the horizontal and thrusting downwards,'' grumbled the Propeller, ``and that's not efficient, though I suppose it's the best we can do until that Inventor fellow finds his Mechanics.''
``Thank you so much,'' said Efficiency. ``I think I have now at any rate an idea of the Elementary Principles of Flight, and I don't know that I care to delve much deeper, for sums always give me a headache; but isn't there something about Stability and Control? Don't you think I ought to have a glimmering of them too?''
``Well, I should smile,'' said a spruce Spar, who had come all the way from America. ``And that, as the Lecturer says, `will be the subject of our next lecture,' so be here again to-morrow, and you will be glad to hear that it will be distinctly more lively than the subject we have covered to-day.''
PART II
THE PRINCIPLES, HAVING SETTLED THEIR DIFFERENCES, FINISH THE JOB
Another day had passed, and the Flight Folk had again gathered together and were awaiting the arrival of Efficiency who, as usual, was rather late in making an appearance.
The crowd was larger than ever, and among the newcomers some of the most important were the three Stabilities, named Directional, Longitudinal, and Lateral, with their assistants, the Rudder, Elevator, and Ailerons. There was Centrifugal Force, too, who would not sit still and created a most unfavourable impression, and Keel-Surface, the Dihedral Angle, and several other lesser fry.
``Well,'' said Centrifugal Force, ``I wish this Efficiency I've heard so much about would get a move on. Sitting still doesn't agree with me at all. Motion I believe in. There's nothing like 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 what we 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 fashionable shade of khaki-coloured fabric, a perfectly stream-lined bonnet, and a bewitching little Morane parasol,[[4]] smiling as usual, and airily exclaiming, ``I'm so sorry I'm late, but you see the Designer's such a funny man. He objects to skin friction,[[5]] and
``Then, if the Pilot is green, my chance will come,'' said the Maximum Angle of Incidence. ``For if the Angle is increased over the Best Climbing Angle, the Drift will rush up; and the Speed, and with it the Lift, will, when my Angle is reached, drop to a point when the latter will be no more than the Weight. The Margin of Lift will have entirely disappeared, and there we shall be, staggering along at my tremendous angle, and only just maintaining horizontal flight.''
``And then with luck I'll get my chance,'' said the Drift. ``If he is a bit worse than green, he'll perhaps still further increase the Angle. Then the Drift, largely increasing, the Speed, and consequently the Lift, will become still less, i.e., less than the Weight, and then--what price pancakes,[[3]] eh?''
[[3]] Pancakes: Pilot's slang for stalling an aeroplane and dropping like a pancake.
``Thank you,'' from Efficiency, ``that was all most informing. And now will you tell me, please, how the greatest Speed may be secured?''
``Certainly, now it's my turn,'' piped the Minimum Angle of Incidence. ``By means of the Elevator, the Pilot places the Aeroplane at my small Angle, at which the Lift only just equals the Weight, and, also, at which we shall make greater speed with no more Drift than before. Then we get our greatest Speed, just maintaining horizontal flight.''
``Yes; though I'm out of the horizontal and thrusting downwards,'' grumbled the Propeller, ``and that's not efficient, though I suppose it's the best we can do until that Inventor fellow finds his Mechanics.''
``Thank you so much,'' said Efficiency. ``I think I have now at any rate an idea of the Elementary Principles of Flight, and I don't know that I care to delve much deeper, for sums always give me a headache; but isn't there something about Stability and Control? Don't you think I ought to have a glimmering of them too?''
``Well, I should smile,'' said a spruce Spar, who had come all the way from America. ``And that, as the Lecturer says, `will be the subject of our next lecture,' so be here again to-morrow, and you will be glad to hear that it will be distinctly more lively than the subject we have covered to-day.''
PART II
THE PRINCIPLES, HAVING SETTLED THEIR DIFFERENCES, FINISH THE JOB
Another day had passed, and the Flight Folk had again gathered together and were awaiting the arrival of Efficiency who, as usual, was rather late in making an appearance.
The crowd was larger than ever, and among the newcomers some of the most important were the three Stabilities, named Directional, Longitudinal, and Lateral, with their assistants, the Rudder, Elevator, and Ailerons. There was Centrifugal Force, too, who would not sit still and created a most unfavourable impression, and Keel-Surface, the Dihedral Angle, and several other lesser fry.
``Well,'' said Centrifugal Force, ``I wish this Efficiency I've heard so much about would get a move on. Sitting still doesn't agree with me at all. Motion I believe in. There's nothing like 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 what we 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 fashionable shade of khaki-coloured fabric, a perfectly stream-lined bonnet, and a bewitching little Morane parasol,[[4]] smiling as usual, and airily exclaiming, ``I'm so sorry I'm late, but you see the Designer's such a funny man. He objects to skin friction,[[5]] and