But Joe Strong knew that a swiftly moving motor-cycle or bicycle has a very strong tendency to follow a straight course. It is easy to keep one's bicycle in a straight line when going fast. There is hardly any need of balancing, and one may ride along even without having the hands on the steering bars.

A motor-cycle moves much faster than a bicycle, and so has a greater chance of keeping in a straight line. This was what Joe was counting on when he proposed to ride on the narrow rail over the high trestle.

He must work rapidly now. It was drawing nearer to the time for the opening of the afternoon performance, and Joe felt that his absence up to this time must be worrying the ring-master, who liked his performers on hand in plenty of time before the show was to open.

Joe looked about for a means of getting up on the rail. It would not do to have some one hold his machine there, and so start. For that would mean his front wheel would swerve more or less because of an endeavor to get his balance, and he would be off the rail almost as soon as he was on it.

"I've got to get a flying start, and hit the rail at a good pace,"

reasoned Joe. "How can I do it?"

Almost at once the answer came to him. Near the place where he and the curious villagers had mounted to the railroad embankment were some planks. They had been taken out of a cattle-guard, to be replaced by new ones.

"I can make a temporary runway of the old planks," reasoned Joe, "and guide myself to the rail with them."

He quickly explained to the men and boys his need. They grasped the idea at once and began to help.

In a few minutes a platform of planks was laid on either side of a rail where it was spiked to the sleepers which were embedded in the cinders.

The trestle started a few feet beyond where the temporary runway, or guiding planks, ended.

Joe used three planks--that is the runway was three planks wide, and they were laid one on either side of the rail, with the middle one directly over the strip of steel. Where the runway came to an end some dirt was used to make an even slope down to the rail, thus taking up the thickness of the plank.

Joe wheeled his machine to the far end of the wooden structure which was made firm by having cinder-dust banked against it. The motor-cycle was held up by willing hands on either side, and Joe started it. With a pop, a rattle and a roar the powerful machine was in motion.

"Let go!" cried Joe, as he threw in the gear.

Off he went. Joe held the handles firm, and his eye was fixed on that shining strip of steel along which--if he had luck--he would soon be speeding.

He opened up the throttle wide. He wanted speed and he needed it as quickly as he could get it, for on speed alone could he depend to keep the machine on the narrow steel path.

Joe heard a shout behind him, and, almost before he knew it, he was at the end of the runway and his front wheel was on the rail.

"So far so good!" thought Joe grimly. If he could only keep the machine there all would be well.

And then began such a ride as probably never before was witnessed. For Joe Strong, holding his machine with firm muscles, his nerves as quiet as only he knew how to make them, his eyes fixed on that shiny strip of steel, was driving his motor-cycle across the high trestle on a single rail.

Below him, at his right hand, was the deep valley, more than a hundred feet down. It was covered with trees and rocks, with here and there a gra.s.sy patch.

"If I fall on that side I hope I can pick out a bit of turf to land on," thought Joe. But he did not intend to fall.

Straight and true he held the front wheel. It needed no pressure on the handle bars. It would keep straight of itself now, for the motor-cycle was going at great speed. That alone would keep it in a true course if no pressure from Joe swerved it. And his hands were on the bars with as delicate a touch as a woman might have used.

In about half a minute Joe was out over the stream which the trestle spanned.

"This would be the best place of all to take a tumble," mused the lad.

He knew if he did fall here he would at least have a chance for his life. For he could kick the machine away from him, and dive into the water. And he felt that it was not too high a fall to take with comparative safety if there was any depth at all to the stream.

But almost before Joe realized it he had flashed over the water, and he was again speeding over the valley itself, with hard ground, rocks, stones and sharp-pointed trees beneath him.

Of course, in case Joe's machine did leave the rail he might fall on the other side. There would be comparative safety, save that he might be badly cut and bruised by the motor-cycle falling on top of him.

On and on he sped. True to the rail he held the front wheel. He was at the height of his speed now, and every second added to his safety, for the faster he went the nearer true to a straight line could he hold the machine.

"Almost over," thought Joe. A quick glance ahead showed him where the trestle came to an end. He had nearly made good his boast.

It was a good mile across the high trestle, and Joe said afterward that he made it in less than a minute. And he must have done so. That rate of speed was necessary in order to keep the machine straight.

Joe looked down. No longer did he see below him the open ties.

He was over the trestle!

He had done what he had said he would do, and crossed on the rail.

With a movement of the handle bars he sent the front wheel down on the cinder bed. He could ride on a broader path now. A little jar, as first one wheel and then the other left the rail, told him that his daring ride was over.

Joe slowed down, and turned to wave a rea.s.suring hand to the crowd at the other end of the trestle. They waved their hands in return, and doubtless they cheered, though Joe could not hear them, as the wind was in the wrong direction.

"Well, that's over!" he said, thankfully enough, though his heart was beating scarcely faster than if he had done some trapeze act, and his nerves were under perfect control.

"I'm glad I didn't meet any train," thought Joe. But he had inquired of his new friends before undertaking the ride about the time of the trains, and had learned that none was scheduled to cross the trestle for some time. Of course there might have been a special, but that did not happen.

Joe was safe. He rode along the even road-bed for some distance and then, following the directions the villagers had given him, he turned down the embankment into a country road. A little later he was on the highway that led to the town where the circus was showing.

"I'll get there just about in time," thought Joe as he looked at his watch.

"Well, I was just thinking about sending out a searching party for you, Joe," remarked Jim Tracy, as our hero rode swiftly up to the show grounds.

"I'm not late," was the reply.

"No. But it was getting near your time, and I wanted to make sure you were on hand."

"Well, I am," replied Joe. But he did not tell until some time afterward what a narrow escape he had had from being late, nor what a risky ride he had taken.

"Oh, Joe, how dared you do it?" asked Helen, when he mentioned it to her. "How dared you? It was so dangerous!"

"Why, I guess I just didn't think anything at all about the danger,"

said Joe with a smile. "I knew it was the only way, and so----"

"You took it," finished Helen. "That's just like you, Joe."

Joe went through his trapeze work in the big tent that afternoon with as much vim and vigor as though he had not, an hour before, taken such a chance with his life. And he followed that up by doing his tank act with his usual success. He did not stay under water quite so long, however, as he found that he was tiring a little, and he wanted to save himself for the night's performance, when a bigger crowd would be present.

And at night Joe went two seconds ahead of his previous best record.

"You'll crowd the world's record yet," predicted Jim Tracy.

The show moved on, and at the next town it received an unexpected bit of advertising. For a reporter in the town where Joe had started on his sensational trestle ride had been given the facts by some of the eyewitnesses, to whom Joe had given his name.

The reporter wrote a thrilling story, and it was published in the paper of the city where the circus was billed the following day.