Then, one day, Joe had his accident. It was not a very serious one, merely the breaking of the motor-cycle transmission chain, but as far as making the machine go without it, Joe might as well have had a bad smash-up.

Helen was not with him, and he was glad of this, for when the break came he was on his way back to the circus grounds, as it was nearing time for the afternoon performance.

Joe tried to mend the chain himself, but a link was needed and he had no spare one. He was looking about on the country road for some place where he could hire a horse and carriage, when he met a small boy who told him there was a garage about a mile away. Joe decided that if he could get his chain repaired he could make better time than by engaging a horse.

Accordingly he pushed the heavy machine along a sandy road until he came to the garage and repair shop. To his delight, the machinist said he could easily repair the chain, and he set about it.

But Joe had consumed more time in his weary walk than he was aware of, and when the chain was mended and he set off again, he had barely time to reach the circus on time, even if he rode at top speed, and had excellent roads all the way.

He was returning by a different route from the one he had taken on going out, and now he regretted it, for the way was longer.

"I'm afraid I'm not going to make it," Joe decided as he looked at his watch. "I've cut my schedule too fine."

He came to a small village and inquired of some loungers if there was not a shorter route to the circus town than the one he had been told to take.

"Well, there is a short cut," said a man, "if you can ride the railroad track. Otherwise you can't get over the river without going five miles out of your way. The railroad bridge over the river is the only one around here, and it's a long, high bridge at that."

"I guess I can ride the railroad," said Joe. "What sort of a bed is it--cracked stone?"

"No, cinders."

Joe was glad to hear that, for cracked stone would have worked havoc to his tires.

"He can't ride no railroad line," declared another man, positively.

"Why not?" Joe wanted to know.

"You can't ride over the railroad trestle, and it's more than a mile long, counting the approaches. If you walk you won't make any better time than if you went around the long way. You can't ride that machine over the open ties. It would rattle it all to pieces. The only way you can do is to walk and push it."

Joe thought for a moment.

"I think I can ride the trestle," he said.

"How?" demanded the man.

"By keeping on the steel rail. That's smooth enough."

"You never can do it!" declared the man who had offered the objection.

"You never can do it in this world. You'll be off in no time, and it's a long fall to the river. You can't do it!"

"Can't I?" asked Joe coolly. "You come and watch me. I'm going to ride my motor-cycle across the railroad trestle bridge on the single rail!"

Several in the crowd looked at him admiringly, while others shook their heads.

"He'll kill himself!" murmured one old man.

"He sure has got nerve!" exclaimed a boy, admiringly.

Meanwhile a crowd of villagers followed Joe as he rode off in the direction of the railroad. It was his only chance of getting to the circus on time.

CHAPTER XXI

IN STRANGE PERIL

Joe was running his machine at reduced speed as he went off in the direction that had been indicated as the location of the railroad tracks. Beside him ran some of the more fleet-footed of the youths of the town, and behind them came some men. All were hurrying to see if Joe would make good his boast.

Yet, it was not so much a boast as it was a determination to do this risky act in order not to be late at the circus and so disappoint a big crowd and cause trouble for the management.

"It's my own fault for going off so far into the country," mused Joe, "and I've got to make up for it as best I can."

"Turn down here to the railroad," a lad called to Joe. "This is the short cut."

Joe steered his machine down a lane, and he soon saw stretching ahead of him the cinder-covered embankment of a single line of railroad. In the distance Joe could see a big depression where the river ran. The stream itself was not very large, but it flowed at the very bottom of a wide and deep valley, and to cross this a long trestle had been necessary.

"Think you can ride it, young man?" asked an elderly man, as Joe halted, for he had to push the machine up the embankment.

"I'm going to make a big attempt," was the answer. "You see, I'm behind my schedule and I've got to make it up."

"You're taking a big risk."

"Well, I'm used to risks," answered Joe with a smile. "I'm a circus trapeze performer."

"That accounts for part of it," went on the man with a smile. "I wish you luck."

"Thanks," murmured Joe as he began to push the heavy motor-cycle up the embankment. Willing hands a.s.sisted him, and he soon stood on the railroad tracks themselves. He found that the road-bed was in good condition. The ties, or sleepers, as the wooden supports of the rails are called, were well embedded in cinders, which had been finely pulverized by the action of the weather and by many feet walking over them, for the railroad tracks were often used as a short cut by the people of the neighborhood.

"This won't be half bad to ride on," said Joe, as he kicked at the cinders.

"No, but the trestle is the sticker," some one remarked. "You can't ride on that without being shaken to pieces on the ties."

"I'm not going to try," Joe said. "As I told you, I'm going to take to a rail."

"You'll never do it!" was the prediction. "I thought you were joking when you said that."

"It's no joke for me if I miss getting to the circus on time," said Joe grimly. "And if you watch you'll at least see me start. I'm not going to guarantee where I'll end," he concluded as he took a careful survey of the trestle which stretched out before him for more than a mile.

Joe was not going into this without having thought carefully of it in advance, in spite of the short time it had taken him to make up his mind. He was used to doing that--thinking and deciding quickly. The very nature of his calling made it necessary for him to do this. One does not have much time to make up one's mind when flying through the air from a high trapeze.

Joe felt reasonably sure that if he could get his machine started at a fast rate of speed, and could get it, at that speed, on top of the smooth, and none too wide, rail, he could hold it there. It is a well-known fact in physics that a body in motion tends to follow a straight line, until forced out of that course by some external force.

If a stone is thrown it will go in a straight line until the attraction of the earth's gravitation pulls it down.

But in Joe's case gravitation would have no effect, as he would be on the ground all the while, or what was practically the ground. What he would have to guard against would be a deviation of more than an inch from left or right. If he swerved ever so little, his machine would leave the rail and he would either plunge over the side of the high trestle, or he would find himself b.u.mping over the ties.

"And I wouldn't want either of those things to happen," mused Joe, with a grim smile on his face.