The prospect of going West, however, was not the main subject of Tom's thoughts at this time. As the weeks pa.s.sed and the end of the six months of experiment came nearer, the inventor was more and more troubled by the princ.i.p.al difficulty which had from the first confronted him. Speed.

That was the mark he had set himself. A maximum speed of two miles a minute on a level track for the Hercules 0001. With the speed already attained by both steam and electric locomotives in the more recent past, this was by no means an impossible attainment, as Tom quite well knew.

But he became convinced that the conditions under which he labored made it impossible for him to be positive of just how great a speed on a straight, level track his invention would attain.

There was no electrified stretch of railroad near Shopton on which the Hercules 0001 might be tested. The track inside the Swift Company's enclosure did not offer the conditions the inventor needed. He felt balked.

"I believe I have hit the right idea in my improvements on the Jandel patents," he told Ned Newton when they were discussing the matter. "But believing is one thing. Knowing is another!"

"Theoretically it works out all right, I suppose?" questioned Ned.

"Quite. I can prove on paper that I've got the speed. But that isn't enough. You can see that."

"Impossible to be sure on the trackage already built here, Tom?"

"I haven't dared give her all she'll take," grumbled Tom. "If I did, I fear she'd jump the rails and I'd have a wreck on my hands."

"And maybe kill yourself!" exclaimed Ned. "You want to have a care."

"Oh, that's all right! I've taken risks before. I don't want to risk the safety of the locomotive, which is more important. That machine has cost us a lot of money."

"I'll say so!" agreed Ned. "You'll have to wait till you can get the locomotive out there on the H. & P. A. tracks before you get a fair speed-test."

"And suppose instead of a triumph it is a fiasco?" Tom said, doubtfully. "I tell you straight, Ned: I never was so uncertain about the outcome of one of my inventions since I began dabbling with motive-power."

"We could build several miles of straight track in the waste ground behind the works," Ned said, thoughtfully.

"Not a chance! There is neither time nor money for such work. Besides, I should have to rebuild my transforming station if I supplied longer conduit wires with current."

"You don't really consider that you have failed, do you, Tom?" and Ned's anxiety made his voice sound very woeful indeed.

"I tell you that my belief doesn't satisfy me. I hate to go West without being sure--positive. I want to know! I have tried the locomotive out in the yard half a dozen times. It runs like a fine watch. There doesn't seem to be a thing the matter with it now. But what speed can I attain?"

"I don't see but you'll have to risk it, Tom."

"I mean to give her one more test. I'll run her out tonight when there is n.o.body about but the watchmen--and you, if you want to come. I'll arrange with the Electric Company for all the current they can spare.

By ginger! I've got to take some risk."

"By the way, Tom," said his chum, "did it ever strike you as odd that that private detective agency never got any trace of O'Malley?"

"Well, he's gone away. We needn't worry about him. Maybe the detective wasn't very smart, at that."

"And yet he was here in town after you put the inquiry on foot. I saw him in the bank. He came there occasionally. And either he, or somebody he hired, placed that bomb in the locomotive."

"All those being facts, what of it?"

"Besides, there was that other fellow--the man with the Vand.y.k.e beard.

Might be a shyster lawyer, or something of the kind. He wasn't spotted, either."

"To tell the truth, I didn't bother to give the Detective Agency the description of that fellow, although you gave it to me," and Tom laughed. "I must confess that I depend more upon my man-trap electric wires to protect the invention than I do on the private inquiry agent."

"It's funny, just the same. If I had another job for a detective I should not submit it to the Blatz Agency," grumbled Ned.

"I fancy Montagne Lewis and his crowd called off their Wild West gunman," said Tom. "In any case, every attempt he made to bother us turned out a fizzle. I am not, however, forgetting precautions, my boy."

Ned Newton realized that his chum had determined to make this night test of the electric locomotive the pivotal trial of the whole affair.

He came back to the works after dinner and was let in by the office watchman at about nine o'clock.

"Mr. Tom here yet?" he asked the man.

"Yes, Mr. Newton. The young boss didn't go home to supper, even. That colored man brought something down for him, and he's in the shed yet."

"Rad is here, you mean?"

"Yes, sir. At least, he didn't go out this way, and we watchmen have instructions to let n.o.body in or out by the yard gates at night."

"I'll say Tom is being careful," thought Ned, as he stepped out through the runway toward the erection shed.

Before he reached the entrance to the huge shed, however, Ned chanced to look down the enclosure. There were several arc lights burning, but even these only furnished a dim illumination for the whole yard.

He supposed that four watchmen were tramping their several beats along the inside of the stockade and close to the trolley-track. But when he saw an instant gleam of light down there, close to the ground, Ned did not believe that it was the flash of a torch in the hand of any sentry.

"Funny," he muttered. "That's outside the fence, or I'm much mistaken.

I wonder now--"

He turned from the door of the shed, left the runway, and began walking toward the distant point at which he had seen the mysterious flash of light.

Chapter XV

The Enemy Still Active

Ned was dressed in a dark business suit, so he was not likely to be observed from a distance, for it was a starless night. Half way to the end of the great yard he began to wonder if the light he had seen might not have been an hallucination.

He doubted very much if anybody was creeping about outside the fence.

The boards were close together, with scarcely a crack half an inch wide anywhere. A light out there--

It flashed again. He was positive of it this time, and of its locality as well. It could be n.o.body who had any honest business about the Swift Construction Company's premises. It was not Koku, for ordinarily the giant would not use an electric torch.

Ned did not know where any of the watchmen were who were acting as sentinels. In fact, as it appeared later, three of them had been called off their beats by Tom himself to help in some necessary task inside the shed. The young inventor was getting ready to run the huge locomotive out upon the yard-track.

Remembering vividly the attempt which had been made some weeks before to blow up the Hercules 0001, it was only natural that Ned should suspect that the flash of light he had seen revealed the presence of some ill-conditioned person lurking just beyond the fence.

A man might be crouching there prepared to hurl an explosive bomb over the fence when the locomotive was brought around as far as that spot.

Or was the villain foolish enough to attempt to enter the enclosure by surmounting the fence?