And, as far as the rifling was concerned, this was true. I will not weary you with the details of how the great core of Tom Swift's giant cannon was bored. Sufficient to say that, after some annoying delays, caused by breaks in the machinery, which had never before been used on such a gigantic piece of work, the rifling was done. After the jackets had been shrunk on, it would be rifled again, to make it true in case of any shrinkage.
Then came the almost Herculean task of shrinking on the great red-hot steel jackets and wire-windings, that would add strength to the great cannon. To do this the central core was set up on end, and the jackets, having been heated in an immense furnace, were hoisted by a great crane over the core, and lowered on it as one would lower his napkin ring over the rolled up napkin.
It took weeks of hard work to do this, and Tom and Ned, with Mr. Damon occasionally for company, remained almost constantly at the plant. But finally the cannon was completed, the rifling was done over again to correct any imperfections, and the manager said:
"Your cannon is completed, Mr. Swift. I want to congratulate you on it. Never have we done such a stupendous piece of work. Only for your plans we could not have finished it. It was too big a problem for us. Your cannon is completed, but, of course, it will have to be mounted. What about the carriage?"
"I have plans for that," replied Tom; "but for the present I am going to put it on a temporary one. I want to test the gun now. It looks all right, but whether it will shoot accurately, and for a greater distance than any cannon has ever sent a projectile before, is yet to be seen."
"Where will you test it?"
"That is what we must decide. I don't want to take it too far from here. Perhaps you can select a place where it would be safe to fire it, say with a range of about thirty miles."
"Thirty miles! why, my dear sir—"
"Oh, I'm not altogether sure that it will go that distance," interrupted Tom, with a smile; "but I'm going to try for it, and I want to be on the safe side. Is there such a place near here?"
"Yes, I guess we can pick one out. I'll let you know."