It took nearly a week to get all the guns mounted, for some of them required considerable work, and it was also necessary to attach gauges to them to register the recoil and pressure.In the meanwhile Tom had been in further communication with government experts who were soon to call on him to inspect the aerial warship, with a view to purchase.
"When are they coming?" asked Ned, as he and Tom went out one morning to make the first test of the guns.
"They will be here any day, now.They didn't set any definite date.I suppose they want to take us unawares, to see that I don't 'frame-up' any game on them.Well, I'll be ready any time they come.Now, Koku, bring along those shells, and don't drop any of them, for that new powder is freakish stuff.""Me no drop any, Master," spoke the giant, as he lifted the boxes of explosives in his strong arms.
The largest gun was loaded and aimed at a distant hill, for Tom knew that if the recoil apparatus would take care of the excess force of his largest gun, the problem of the smaller ones would be easy to solve.
"Here, Rad, where are you going?" Tom asked, as he noticed the colored man walking away, after having completed a task assigned to him.
"Where's I gwine, Massa Tom?" "Yes, Rad, that's what I asked you.""I--I'se gwine t' feed mah mule, Boomerang," said the colored man slowly."It's his eatin' time.jest now, Massa Tom.""Nonsense! It isn't anywhere near noon yet.""Yais, sab, Massa Tom, I knows dat," said Eradicate, as he carefully edged away from the big gun, "but I'se done changed de eatin' hours ob dat mule.He had a little touch ob indigestion de udder day, an' I'se feedin' him diff'rent now.So I guess as how yo'll hab t' 'scuse me now, Massa Tom.""Oh, well, trot along," laughed the young inventor."I guess we won't need you.Is everything all right there, Koku?""All right, Master."
"Now, Ned, if you'll stand here," went on Tom, "and note the extreme point to which the hand on the pressure gauge goes, I'll be obliged to you.
Just jot it down on this pad."
"Here comes someone," remarked the bank clerk, as he saw that his pencil was sharpened.He pointed to the field back of them.
"It's Mr.Damon," observed Tom."We'll wait until he arrives.He'll be interested in this.""Bless my collar button, Tom! What's going on?" asked the eccentric man, as he came up."Has war been declared?""Just practicing," replied the young inventor."Getting ready to put the armament on my aerial warship.""Well, as long as I'm behind the guns I'm all right, I suppose?" "Perfectly," Tom replied."Now then, Ned, I think we'll fire."There was a moment of inspection, to see that nothing had been forgotten, and then the big gun was discharged.There was a loud report, not as heavy, though, as Ned had expected, but there was no puff of smoke, for Tom was using smokeless powder.Only a little flash of flame was observed.
"Catch the figure, Ned!" Tom cried.
"I have it!" was the answer."Eighty thousand!""Good! And I can build a recoil check that will take up to one hundred and twenty thousand pounds pressure.That ought to be margin of safety enough.Now we'll try another shot."The echoes of the first had hardly died away before the second gun was ready for the test.That, too, was satisfactory, and then the smaller ones were operated.These were not quite so satisfactory, as the recoil developed was larger, in proportion to their size, than Tom had figured.
"But I can easily put a larger hydrostatic check on them," he said."Now, we'll fire by batteries, and see what the total is."Then began a perfect bombardment of the distant hillside, service charges being used v, and explosive shells sent out so that dirt, stones and gravel flew in all directions.Danger signs and flags had been posted, and a cordon of Tom's men kept spectators away from the hill, so no one would be in the danger zone.
The young inventor was busy making some calculations after the last of the firing had been completed.Koku was packing up the unfired shells,and Mr.Damon was blessing his ear-drums, and the pieces of cotton he had stuffed in to protect them, when a tall, erect man was observed strolling over the fields in the direction of the guns.
"Somebody's coming, Tom," warned Ned.
"Yes, and a stranger, too," observed Tom."I wonder if that can be Eradicate's Frenchman?"But a look at the stranger's face disproved that surmise.He had a frank and pleasant countenance, obviously American.
"I beg your pardon," he began, addressing everyone in general, "but I am looking for Tom Swift.I was told he was here.""I am Tom Swift," replied our hero.
"Ah! Well, I am Lieutenant Marbury, with whom you had some correspondence recently about--""Oh, yes, Lieutenant Marbury, of the United States Navy," interrupted Tom."I'm glad to see you," he went on, holding out his hand."We are just completing some tests with the guns.You called, I presume, in reference to my aerial warship?""That is it--yes.Have you it ready for a trial flight?""Well, almost.It can be made ready in a few hours.You see, I have been delayed.There was a fire in the plant"A fire!" exclaimed the officer in surprise."How was that? We heard nothing of it in Washington.""No, I kept it rather quiet," Tom explained."We had reason to suspect that it was a fire purposely set, in a shed where I kept a quantity of explosives.""Ha!" exclaimed Lieutenant Marbury."This fits in with what I have heard.And did you not receive warning?" he asked Tom.
"Warning? No.Of what?"
"Of foreign spies!" was the unexpected answer."I am sorry.Some of our Secret Service men unearthed something of a plot against you, and I presumed you had been told to watch out.If you had, the fire might not have occurred.There must have been some error in Washington.But let me tell you now, Tom Swift--be on your guard!"
