CHAPTER XI
ENGINEERING
Two busy days followed during which Bill and Gus went to the city withProfessor Gray to purchase materials in full for the power plant. Theyalso had cement, reinforcing iron, lumber for forms and a small toolhouse hauled out to the power site and they drove the first stakes toshow the position of wheel and pipe line. Mr. Hooper did not put in anappearance.
On the third morning the Professor bade the boys good-by, exacting thepromise that they would write frequently of their progress. They hadprivately formed an engineering company with Professor Gray aspresident, Gus as vice-president, which was largely honorary, and Billas general manager and secretary. Advance payments necessary for extralabor and their own liberal wages were deposited at the Fairview Bank byProfessor Gray and the boys were given a drawing account thereon, with asimple expense book to keep.
That afternoon, dressed in new overalls and blouses, with a big,good-natured colored man to help with the laboring work, the boys wereearly on the job, at first making a cement mixing box; then Bill drovethe center stake thirty feet below where the dam was to be placed andfrom which, using a long cord, the curve of the structure twenty-ninefeet wide, was laid out upstream.
At the spot chosen the rock-bound hillsides rose almost perpendicularlyfrom the narrow level ground that was little above the bed of thestream; it was the narrowest spot between the banks. George, the coloredfellow, was set to work digging into one bank for an end foundation; theother bank held a giant boulder.
The boys were giving such close attention to their labors that they didnot see observers on the hilltop. Presently the gruff voice that theyhad heard before hailed them from close by and they looked up to see Mr.Hooper and the slim youth approaching. The boys had heard that thisThaddeus was the old man's nephew and that he called the Hooper mansionhis home.
"What you drivin' that there stake down there for? Up here's where thePerfesser said the dam was to set," Mr. Hooper demanded.
"Yes, right here," Bill replied. "But it is to be curved upstream andthat stake is our center."
"What's the idea of curvin' it?"
"So that it will be stronger and withstand the pressure. You can't breakan arch, you know, and to push this out the hills would have to spreadapart."
"I kind o' see." The old man was thoughtful and looked on silently whilethe dam breast stakes were being driven every three feet at the end of astretched cord, the other end pivoting on the center stake below, thisgiving the required curve.
"How deep you goin' into that hill? Seems like the water can't git roundit now." Mr. Hooper, at a word from Thad, seemed inclined to criticize.
"We must get a firm end, preferably against rock," Bill explained.
"Shucks! Reckon the clay ain't goin' to give none. How much fall yougoin' to git on that Pullet wheel?"
"Pelton wheel. About eighty feet, Professor Gray figured it roughly.We'll take it later exactly."
"Kin you improve on the Perfesser?"
"No, but he made only a rough calculation. We'll take it both by levelsand by triangulation, using an old sextant of the Professor's. It isn'ta diff----"
"What's try-angleation?" Mr. Hooper was becoming interested.
"The method of reading angles of different degrees and in that waygetting heights and distances. That's the way they measure mountainsthat can't be climbed and tell the distance of stars."
"Shucks, young feller! I don't reckon anybody kin tell the distance o'the stars; they only put up a bluff on that. They ain't no ackshall wayo' gittin' distance onless you lay a tape measure, er somethin' like iton the ground. These here surveyors all does it; I had 'em go round myplace."
Bill smiled and shook his head. "I guess you just haven't given it anyconsideration. There are lots of easier and better ways. Triangulation.Now, for instance, suppose an army comes to a wide river and wants toget across. They can't send anybody over to stretch a line; there may beenemy sharp-shooters that would get them and it is too wide, anyway. Butthey must know how many pontoon boats and how much flooring plank theymust have to bridge it and so they sight a tree or a rock on the othershore and take the distance across by triangulation. Or suppose--"
"Never heard of it. Why wouldn't surveyors git from here to yan thata-way, 'stead o' usin' chains? Could you----?"
"Chaining it is a little more accurate, where they have a lot of curvesand angles and the view is cut off by woods and hills. Yes, we can worktriangulation; we could tell the distance from the hilltop to your houseif we could see it and we had the time."
"Bunk! Don't let 'em bluff you that a-way, Uncle. Make 'em prove it."Thad showed his open hostility thus.
Gus dropped his shovel and came from the creekside where he had begun todig alongside of the stakes for the foundation. He was visibly and, forhim, strangely excited as he walked up to Thad.
"See here, fellow, Bill can do it and if there is anything in it we willdo it, too! You are pretty blamed ignorant!"
Mr. Hooper threw back his head and let out a roar of mirth. "Well, Ireckon that hits me, too. An' I reckon it might be true in a lot o'things. But Thad an' me, we kind o' doubt this."
"We sure do. I'd bet five dollars you couldn't tell it within half amile an' it ain't much more than that."
"I'll take your bet and dare you to hold to it," said Gus.
"Bet 'em, Thad; bet 'em! I'll stake you."
"Oh, we don't want your money; betting doesn't get anywhere and it isn'tjust square, anyway." Bill was smilingly endeavoring to restore goodfeeling. "Now, Mr. Hooper, we're not fixed to make a triangulationmeasurement to-day, but----"
"Not fixed? Of course not. Begins with excuses," sneered Thad.
"But to-morrow we'll bring out Professor Gray's transit and show you theway it's done."
"Oh, yes, Uncle; they'll show us--to-morrow, or next day, or next week.Bunk!" Thad was plainly trying to be offensive.
"You'll grin on the other side of your hatchet face, fellow, when we doshow you," said Gus.
"Now, Gus, cut out the scrapping. You can't blame him, nor Mr. Hooper,for doubting it if they've never looked into the matter. We can bringthe transit out this afternoon for taking the levels. Be here afterdinner, Mr. Hooper, if you can."
"I'll be here, lads," said the ex-cattle-dealer. "An' I reckon mynephew'll come along, too."