CHAPTER XIII
AT WORK ON THE AEROPLANE
The following day the first box of material arrived from Kansas City,and was taken to Mr. Giles' machine shop, which, having formerly beenthe army stables, was a great deal larger than was needed for themachinist's work, and he was able to give Hawke and the boys a roomyspace at the rear.
A box from Denver came on Monday morning, and in the afternoon there wasa consignment from New York. The engine was to be sent by freight fromFort Omaha, and would take some time to reach Silver City, but, as Hawkeexplained, it was the last thing to be used and the delay would notmatter.
By Wednesday morning, therefore, which was the day after the Fourth, allwas ready to go ahead on the aeroplane. The Fourth had been unusuallyquiet for the boys because Herb could not take part in any activefestivities. While his injury had been slight, and was now practicallyhealed, his father insisted that he should remain perfectly quiet andnot become excited by unwarranted celebration. This was a hardship forso active a boy as Herb, but to please his father he obeyed withoutcomplaint.
As reparation, the rancher ordered a lavish display of fireworks fromAlbuquerque, and in the evening the boys were entertained by anexhibition that was worthy of young princes.
The exhilaration which followed this event, their sympathy for Herb, thegratitude they felt for the generous rancher, and their eagerness tosolve the mystery of the Bread Pudding ranch, which was heightened bythe incidents of the last few weeks, coupled with their growing interestin aviation, gave the boys an enthusiasm for the work of constructingthe biplane which guaranteed success.
Hawke set up his model in the shop for their guidance, and, desiring tostart them with fundamentals, he dissected the wing of a hawk, and, thefirst thing Wednesday morning, explained to them the first principles ofplane construction, using the formation of the wing as an illustration.
"The early planes were straight," he explained, "but we have sincelearned that the curved surfaces are far more efficient. Keep in mindthe idea of the bird, the shape of his wings, and you have the bestworking basis for building a plane." The aviator believed, with someother specialists, that examples taken from nature were the best sort ofinstruction for the novice.
The materials were unpacked, including all necessary tools, and withoutwasting much time on preliminaries, the boys set heartily to work.
"I am planning to equip this machine with swinging wing ends," saidHawke. "This is something not used on many biplanes, but it will benecessary to have them if we are to follow the maneuvers of a bird. Ifthe wing tips are made with a down curve at their ends, the result ofswinging them to the rear will be to increase the lifting power, whileat the same time reducing the resistance of the air to forward movement.This would afford an ideal method of steering, being exactly like thatemployed by birds."
Later, when work was begun on these wing tips, the boys fully understoodHawke's theory.
Another innovation which Hawke planned for the machine was a mica windowin the forward part of the fuselage, which would enable them to see whatwas passing below them, without leaning over or altering the angle ofthe planes.
While the boys worked and followed directions, Hawke explained the partsand their use on the machine. Fred and Fly proved themselves the mostaccomplished at first, owing to their previous experience with mechanicsand aeroplanes. Gray also had a previous knowledge of the possibilitiesof aeronautics, and it was not long before all of the boys wereintelligently working on Hawke's model and making progress.
Mr. Phipps rode over from the ranch almost every day to see them atwork, and was much pleased with the rapid advance his son was making.Entirely recovered from the accident, Herb was as useful as any of hiscompanions, and, besides evincing a great deal of mechanical skill,which he had never been called upon to display before, he readilygrasped the principles Hawke continually ground into his pupils.
"You see, Dad," Herb said, when the rancher had inquired, on theoccasion of one of his visits five or six days after work had beenbegun, about the use of the propeller, the particular part on which Herbwas working, "the propeller is everything on an aeroplane. It's got tobe made just right, or the whole thing goes to smash. If it wasn't forthe propeller the machine wouldn't go at all," he finished triumphantly.
"Oh, indeed," remarked the southerner, an amused twinkle in his eye."And what's the reason for that?"
"Well, yuh see," replied Herb, seriously, not noticing the smile playingabout his father's mouth, and anxious to display his newly acquiredknowledge, "it's the thing that moves the machine forward, and it hasalmost everything to do with the pitch and speed. The surfaces of theaeroplane are called the skin, and there is some friction of air againstthese surfaces, and that is called skin friction. Well, yuh see, thepropeller has to make the machine move through the air with the smallestamount of skin friction. It has to travel through as large an amount ofair as possible in a certain time, and take as little power as possible.Yuh understand?"
"Oh, yes," exclaimed the rancher, unable to restrain a short laugh. "Howabout that, Hawke?"
"He's right," responded the aviator, slapping his young pupil on theback. "He's got the dope exactly."
"Yes, but a good deal depends on the operator," chipped in Fly, who wasambitious to excel as an aviator, and could scarcely wait until themachine was finished to try his hand.
"I'm working on the box-girder," said Dunk, feeling called upon to givean account of himself.
"What's that," asked Mr. Phipps indulgently.
"It's the part that really bears the greatest weight--a sort of a beamwith the weight in the center, fixed so it bears the load equallydistributed. You can see one on Hawke's model."
"And one of the important things," said Jerry, not to be outdone, "is tobuild the plane so the guy wires remain taut, and the main spars, ribsand struts are properly placed."
"Yes, and then we have to remember to build it as light as we can and asstrong as we can," put in Gray. "We want to go fast, but we don't wantaccidents, so we can't make it as light as we'd like. Oftentimes we haveto make a part heavier to be sure it's strong enough."
Other technical information was glibly imparted when Captain Crawforddropped in occasionally. Dr. Rivers also paid the shop frequent visits,while the ladies did not neglect to show an interest in the work.
In fact, everyone in and about the fort shared the enthusiasm of theyoung aviators, and the aeroplane got to be the most important topic ofconversation. Hawke was obliged to put a sign on the door of the shop:"NO ADMITTANCE," in order to keep away the soldiers, Greasers, loafers,and even Indians who had a habit of dropping in and interrupting thework.
About eight days after construction started they were ready for ahangar. As Mr. Phipps sent over two of his idle Greasers to erect this,work on the aeroplane was not stopped. The shed was erected just northof the machine shop, facing the old parade grounds, which was an idealspot for the first try-out.
"I'm anxious to test my new feature of equalizing the stress anddistribution of weight," Hawke explained to Mr. Phipps, who had comeover with the Greasers. "I want to be able to carry all of the boys, ifpossible, and this is a difficult feat, for the greater the number ofpassengers carried the greater is the tax on the stability of themachine. The boys have shown such unusual ability in carrying out myideas, however, that I think I am going to be able to perfect the deviceand prove its efficiency in a flight or two."
The day the hangar was completed, the engine arrived. A small truckwhich Mr. Giles had in the shop was to be used in wheeling the aeroplaneout of the shop through the big middle doors of the stable, and into thehangar.
"My, ain't she a beautiful bird," exclaimed Jerry, when they put awaytheir tools, and were proudly viewing the result of their work, for theaeroplane was set up complete with the exception of the engine, andstood mounted on the small wheeled truck ready for removal. A trialflight was to be made in the morning.
"You can't beat that anywhere in the world," said Dunk
, proudly.
"I almost feel as though she were alive," commented Herb.
"I must say you did a mighty fine job, boys," said Hawke, "and if sheflies as well as she looks, we'll put in our application for medals."
"Is there any chance that she won't fly?" asked Fly anxiously.
"You never know what a brand new plane is going to do," responded Hawke,"and you're never sure till you're gliding safely up in the air, whetheror not all the cogs are in tight. But I don't think there's much dangerthat this one won't fly."
"We'll steer straight for that old tower," said Jerry, "and see if wecan't roust out the Thunder Bird--or devil bird, whatever it is."
"Better watch for it some dark night near the sheep fold," suggestedHerb. "It's about due to be around here now. We haven't seen it for sometime. But another rancher several miles north of father says he's hadsome sheep hurt and taken, so I suppose it's shifted its hunting groundfor a while."
"Gee, I'm awful anxious to find out just what it is anyway," exclaimedFred. "Certainly is a mysterious animal."
"Have you seen that old Indian snooping around here?" inquired Herb,changing the subject. "I saw him a minute or two ago peeping in throughthe door over there, but I didn't say anything at the time."
"Oh, I suppose he has some superstitious idea that this is a destroyingevil spirit we're building," said Carl. "Only I wish he would keep away.The way he stands around and peers makes me nervous."
"He doesn't seem to pay any attention to the "No Admittance" sign,"remarked Hawke, smiling.
"Suppose he can't read English," said Carl. "But I have a sneakingsuspicion that he can understand it. It's an old trick of the Indian tostand around and look as innocent as a brick wall, and yet take ineverything you say."
"We've been talking a lot about the Thunder Bird lately," observed Fly."Maybe that's interested him."
"I wouldn't be surprised if he's planning some deviltry," Carl remarkedas they left the shop. "He's got some exaggerated notion about theThunder Bird already."
As they entered the parade grounds they saw the retreating form of thestrange Indian.
"I'll bet he's been listening," exclaimed Carl, a little disturbed."There's no tellin' what a half-cracked, superstitious Indian may getinto his head."