Radio Boys Loyalty Part 7

"Will you let Grier do it? He knows that old trick, and he is handier with the chalk than I."

Gus went forward, took a two-foot rule from his pocket and laying off two parallel lines seventeen and three-eighths inches apart, laid the rule diagonally across them so that the s.p.a.ce would measure twenty inches. Then he ticked off at the figures four, eight, twelve and sixteen. Laying the rule straight across from an outer line to the first tick he turned and announced:

"Each s.p.a.ce is practically three and fifteen-thirty-seconds inches."

This brought forth something like applause, along with many very audible remarks, such as: "Pretty cute." "Handy." "Where'd he get it?" "Can't fool either of 'em, can you?" "Those fellows are practical, that's sure."

Mr. Davidson smiled sort of absently. He had to give approval, but dropped the question rather abruptly, going back to his last problem.

"Now, see if you can tell me this: I have a half-pint cup even full of water, the liquid exactly level with the edge of the gla.s.s. About how many one-inch brads must I drop into the cup before the water overflows?

Water, you understand--not oil, nor mola.s.ses. This is an old experiment and it concerns a well-known physical law. If anyone has seen it done he will kindly remain silent. Now, who will make a guess as to the number of nails?"

Every brow was wrinkled, except those of a few conclusion jumpers of whom there must be some in every crowd. One of these latter fellows shouted at once: "About a half dozen and it'll slop over!"

"It'll take only one or two," said another.

"Not more than a dozen, anyway."

But the others, mostly lads capable of real mental exercise, were all cudgeling their brains. It was a subject which had much to be taken into consideration. Presently one senior spoke up:

"It ought to take more than an ounce of them."

"Nearly as much, anyway."

"More. That'll fool you mightily."

"It looks as though a few brads would do it, but it will take a lot."

"And why?" asked Mr. Davidson. "Come, what do you say about this?" He again appealed to Bill, turning then also to Gus.

"Well, sir, I think I can see that it will take nearly all of that box of brads, perhaps a hundred. It is a matter of cohesion and even water possesses that, so that to overflow, it will have to rise a good deal above the rim. The area of the gla.s.s plus the rise that will be required for the overflow will be, in solid contents, easily as much as that box of loosely filled brads; if they were melted down they wouldn't be greater than the water area. It is a good deal like the loading of a boat: the displacement is a uniform, compact ma.s.s; the load is a jumble with more air s.p.a.ce than material. And it is like the floating of a heavy iron pot."

For answer the lecturer turned and drew a half-pint of water in a gla.s.s, brought from his pocket a box of brads and began dropping, one at a time and counting, them into the water. There was profound silence. As the number increased, reaching above two score of the small nails, there began to be heard comments here and there.

"Zowie! Who'd a thunk it?"

"Better just dump 'em all in and start over."

"Don't reckon those nails are soaking the water up; eh?"

"If it were mola.s.ses you could fill it half full of brads before it would slop over."

"Say, look, he's up to sixty! Would you believe that?"

"Hey there, Fatty, you guessed one nail; didn't you----"

"Sixty-eight, sixty-nine, seventy; looks to me like a spill pretty soon."

"When the freshet starts----"

"It'll drown a lot of people."

Mr. Davidson stopped dropping the nails into the tumbler and held up his hand.

"There it goes, boys--the first drop over! Eighty-two brads. You can see who guessed best. The cohesion of the liquid explains it, as our young friend here has said. I'm glad you have one thinker among you. Now I want to tell you something about the installation of machinery by individual motors driven by a central generator, as compared to the drive from a mill long countershaft and pulleys." And he proceeded with his talk.

Yes, the lightning had struck. From this moment the respect shown to Bill, and to Gus also, by those who had no desire to do otherwise was really almost overdone, his cla.s.smates being generally proud of him, and the teachers and seniors pleased to have him a member of the school. But the sophs mostly grew more inclined to consider both boys a menace to their peace of mind.

CHAPTER XIII

QUICK WORK

"I must have to report to you the utter spoil of your shop and your work; also my own complete!" Such was the breath-taking remark of Tony Sabaste, as he stuck his head into the room of Bill and Gus and regarded the boys at their studies soon after daylight.

With no more than a word of surprise or doubt the young mechanics followed their Italian friend into the bas.e.m.e.nt and were not long in finding his words true.

The crown plate of the drill had been broken in two with a hammer and probably the same means had been used to crack the lathe pulley and smash some of the tools. Materials were not harmed, but the work just begun on two new radio sets of the better value, along with Tony's efforts, was reduced to splinters.

The door of the shop had never been locked; the miscreant had entered in the night and engaged in the work of destruction.

"Well, who----?" began Bill.

"Ah, say not that question," said Tony. "Do not you know? Is there a doubt; even one? I have no enemy in the school but one, and who else----"

"Oh, sure, anyone but friendly, innocent Bill would know. Malatesta, of course."

Gus was ready with short cuts to names as well as to problems, his genius for detection having been proved in a like instance, before this.

He went over and picked up a hammer, holding it by the head and scanning the handle.

"Here, I suppose, are some thumb prints," he said; "it only remains for us to get hold of----"

Gus was interrupted by the sudden entrance of a member of the senior cla.s.s, Jim Lambert, who had but a few days before completed a crystal radio set in the shop. He gazed about him.

"About as I thought. This is rotten, fellows, and if I know anything, it is going to be paid for."

"Who will--?" began Bill.

"Let me tell you. I room right above here, as you know. Late last night, very late, probably toward morning, I was wakened by a noise. I listened and heard the sound of a blow that was surely down here. Then I heard some more noises, m.u.f.fled, though,--the floor, you know, is fire-proofed and thick. I didn't wake Smith, but I got up and went to the door and looked out. I hadn't been there two minutes before I was aware that someone came up out of the bas.e.m.e.nt and was standing in the hall. I think he must have suspected something, for he came along toward my door and I got inside and closed it, with my hand on the k.n.o.b so as not to click the latch. Then I felt a pressure on the door--the fellow had the nerve to try it. He wanted to see if it was open, probably thinking it was left ajar and he may have seen the light from the window, pulled it open then and there he was--pretty much through the door before I closed it. Well, I just surprised, I guess."

"Who, who?" from Bill.

"Why, Malatesta, of course," said Gus, with positive finality.

"Say, young fellow, you've got it. Good guesser. He must have some grudge against----"