"Hurray!" he cried in delight."She stood the charge all right.And look! look!" he cried, as he pointed the glasses toward the distant hillside.
"There goes my projectile as straight as an arrow.There! By Caesar, Ned! It landed within three feet of the target! Oh, you beauty!" he yelled at his giant cannon."You did all I hoped you would! Thirty miles, Ned! Think of that! A two- ton projectile being shot thirty miles!""It's great, Tom!" yelled his chum, clapping him on the back, and capering about."It's the longest shot on record.""It certainly is," declared the foreman of the steel workers, who had helped in casting many big guns."No cannon ever made can equal it.You win, Tom Swift!""Bless my armor plate!" gasped Mr.Damon."What attacking ship against the Panama Canal could float after a shot like that.""Not one," declared Tom; "especially after I put a bursting charge into the projectile.We'll try that next."By means of compressed air the gases and some particles of the unexploded powder were blown out of the big cannon.Then it was loaded again, the projectile this time carrying a bursting charge of another explosive that would be set off by concussion.
Once more they retired to the bombproof, and again the great gun was fired.Once more the ground shook, and they were nearly deafened by the shock.
Then, as they looked toward the distant hillside, they saw a shower of earth and great rocks rise up.It was like a sand geyser.Then, when this settled back again, there was left a gaping hole in the side of the mountain.
"That does the business!" cried Tom."My cannon is a success!"The last shot did not go quite as far as the first, but it was because a different kind of projectile was used.Tom was perfectly satisfied, however.Several more trials were given the gun, and each one confirmed the young inventor in his belief that he had made a wonderful weapon.
"If that doesn't fortify the Panama Canal nothing will," declared Ned."Well, I hope I can convince Uncle Sam of that," spoke Tom, simply.
The muzzle velocity and the pressure were equal to Tom's highest hopes.He knew, now, that he had hit on just the right mixture of powder, and that his gun was correctly proportioned.It showed not the slightest strain.
"Now we'll try another bursting shell," he said, after a rest, during which some records were made."Then we'll call it a day's work.Koku, bring up some more powder.I'll use a little heavier charge this time."It was while the gun was being loaded that a horseman was seen riding wildly down the valley.He was waving a red flag in his hand.
"Bless my watch chain!" cried Mr.Damon."What's that?""It looks as though he was coming to give us a warning," suggested the steel foreman.
"Maybe someone has kicked about our shooting," remarked Ned."I hope not," murmured Tom.
He looked at the horseman anxiously.The rider came nearer and nearer, wildly waving his flag.He seemed to be shouting something, but his words could not be made out.Finally he came near enough to be heard."The dam! The dam!" he cried."It's bursting.Your shots have hastenedit.The cracks are widening.You'd better get away!" And he galloped on."Bless my toilet soap!" gasped Mr.Damon.
"I was afraid of this!" murmured Tom."But, since our shots have hastened the disaster, maybe we can avert it.""How?" demanded Ned.
"I'll show you.All hands come here and we'll shift this gun.I want it to point at that big white stone!" and he indicated an immense boulder, well up the valley, near the place where the two great gulches joined.
