The greatest people have their weak points, and the best-behaved boys now and then yield to temptation and get into trouble, as everybody knows. Frank was considered a remarkably well-bred and proper lad, and rather prided himself on his good reputation, for he never got into scrapes like the other fellows. Well, hardly ever, for we must confess that at rare intervals his besetting sin overcame his prudence, and he proved himself an erring, human boy. Steam-engines had been his idols for years, and they alone could lure him from the path of virtue. Once, in trying to investigate the mechanism of a toy specimen, which had its little boiler and ran about whistling and puffing in the most delightful way, he nearly set the house afire by the sparks that dropped on the straw carpet. Another time, in trying experiments with the kitchen tea-kettle, he blew himself up, and the scars of that explosion he still carried on his hands.

He was long past such childish amusements now, but his favorite haunt was the engine-house of the new railroad, where he observed the habits of his pets with never-failing interest, and cultivated the good-will of stokers and brakemen till they allowed him many liberties, and were rather flattered by the admiration expressed for their iron horses by a young gentleman who liked them better even than his Greek and Latin.

There was not much business doing on this road as yet, and the two cars of the passenger-trains were often nearly empty, though full freight-trains rolled from the factory to the main road, of which this was only a branch. So things went on in a leisurely manner, which gave Frank many opportunities of pursuing his favorite pastime. He soon knew all about No. 11, his pet engine, and had several rides on it with Bill, the engineer, so that he felt at home there, and privately resolved that when he was a rich man he would have a road of his own, and run trains as often as he liked.

Gus took less interest than his friend in the study of steam, but usually accompanied him when he went over after school to disport himself in the engine-house, interview the stoker, or see if there was anything new in the way of brakes.

One afternoon they found No. 11 on the side-track, puffing away as if enjoying a quiet smoke before starting. No cars were attached, and no driver was to be seen, for Bill was off with the other men behind the station-house, helping the expressman, whose horse had backed down a bank and upset the wagon.

"Good chance for a look at the old lady," said Frank, speaking of the engine as Bill did, and jumping aboard with great satisfaction, followed by Gus.

"I'd give ten dollars if I could run her up to the bend and back," he added, fondly touching the bright brass knobs and glancing at the fire with a critical eye.

"You couldn't do it alone," answered Gus, sitting down on the grimy little perch, willing to indulge his mate's amiable weakness.

"Give me leave to try? Steam is up, and I could do it as easy as not;" and Frank put his hand on the throttle-valve, as if daring Gus to give the word.

"Fire up and make her hum!" laughed Gus, quoting Bill's frequent order to his mate, but with no idea of being obeyed.

"All right; I'll just roll her up to the switch and back again. I've often done it with Bill;" and Frank cautiously opened the throttle-valve, threw back the lever, and the great thing moved with a throb and a puff.

"Steady, old fellow, or you'll come to grief. Here, don't open that!" shouted Gus, for just at that moment Joe appeared at the switch, looking ready for mischief.

"Wish he would; no train for twenty minutes, and we could run up to the bend as well as not," said Frank, getting excited with the sense of power, as the monster obeyed his hand so entirely that it was impossible to resist prolonging the delight.

"By George, he has! Stop her! Back her! Hold on, Frank!" cried Gus, as Joe, only catching the words "Open that!" obeyed, without the least idea that they would dare to leave the siding.

But they did, for Frank rather lost his head for a minute, and out upon the main track rolled No. 11 as quietly as a well-trained horse taking a familiar road.

"Now you've done it! I'll give you a good thrashing when I get back!" roared Gus, shaking his fist at Joe, who stood staring, half-pleased, half-scared, at what he had done.

"Are you really going to try it?" asked Gus, as they glided on with increasing speed, and he, too, felt the charm of such a novel adventure, though the consequences bid fair to be serious.

"Yes, I am," answered Frank, with the grim look he always wore when his strong will got the upper hand. "Bill will give it to us, any way, so we may as well have our fun out. If you are afraid, I'll slow down and you can jump off," and his brown eyes sparkled with the double delight of getting his heart's desire and astonishing his friend at the same time by his skill and coolness.

"Go ahead. I'll jump when you do;" and Gus calmly sat down again, bound in honor to stand by his mate till the smash came, though rather dismayed at the audacity of the prank.

"Don't you call this just splendid?" exclaimed Frank, as they rolled along over the crossing, past the bridge, toward the curve, a mile from the station.

"Not bad. They are yelling like mad after us. Better go back, if you can," said Gus, who was anxiously peering out, and, in spite of his efforts to seem at ease, not enjoying the trip a particle.

"Let them yell. I started to go to the curve, and I'll do it if it costs me a hundred dollars. No danger; there's no train under twenty minutes, I tell you," and Frank pulled out his watch. But the sun was in his eyes, and he did not see clearly, or he would have discovered that it was later than he thought.

On they went, and were just rounding the bend when a shrill whistle in front startled both boys, and drove the color out of their cheeks.

"It's the factory train!" cried Gus, in a husky tone, as he sprang to his feet.

"No; it's the five-forty on the other road," answered Frank, with a queer thrill all through him at the thought of what might happen if it was not. Both looked straight ahead as the last tree glided by, and the long track lay before them, with the freight train slowly coming down. For an instant, the boys stood as if paralyzed.

"Jump!" said Gus, looking at the steep bank on one side and the river on the other, undecided which to try.

"Sit still!" commanded Frank, collecting his wits, as he gave a warning whistle to retard the on-coming train, while he reversed the engine and went back faster than he came.

A crowd of angry men was waiting for them, and Bill stood at the open switch in a towering passion as No. 11 returned to her place unharmed, but bearing two pale and frightened boys, who stepped slowly and silently down, without a word to say for themselves, while the freight train rumbled by on the main track.

Frank and Gus never had a very clear idea as to what occurred during the next few minutes, but vaguely remembered being well shaken, sworn at, questioned, threatened with direful penalties, and finally ordered off the premises forever by the wrathful depot-master. Joe was nowhere to be seen, and as the two culprits walked away, trying to go steadily, while their heads spun round, and all the strength seemed to have departed from their legs, Frank said, in an exhausted tone, -

"Come down to the boat-house and rest a minute."

Both were glad to get out of sight, and dropped upon the steps red, rumpled, and breathless, after the late exciting scene. Gus generously forebore to speak, though he felt that he was the least to blame; and Frank, after eating a bit of snow to moisten his dry lips, said, handsomely, -

"Now, don't you worry, old man. I'll pay the damages, for it was my fault. Joe will dodge, but I won't, so make your mind easy.

"We sha'n't hear the last of this in a hurry," responded Gus, relieved, yet anxious, as he thought of the reprimand his father would give him.

"I hope mother won't hear of it till I tell her quietly myself. She will be so frightened, and think I'm surely smashed up, if she is told in a hurry;" and Frank gave a shiver, as all the danger he had run came over him suddenly.

"I thought we were done for when we saw that train. Guess we should have been if you had not had your wits about you. I always said you were a cool one;" and Gus patted Frank's back with a look of great admiration, for, now that it was all over, he considered it a very remarkable performance.

"Which do you suppose it will be, fine or imprisonment?" asked Frank, after sitting in a despondent attitude for a moment.

"Shouldn't wonder if it was both. Running off with an engine is no joke, you know."

"What did possess me to be such a fool?" groaned Frank, repenting, all too late, of yielding to the temptation which assailed him.

"Bear up, old fellow, I'll stand by you; and if the worst comes, I'll call as often as the rules of the prison allow," said Gus, consolingly, as he gave his afflicted friend an arm, and they walked away, both feeling that they were marked men from that day forth.

Meantime, Joe, as soon as he recovered from the shock of seeing the boys actually go off, ran away, as fast as his legs could carry him, to prepare Mrs. Minot for the loss of her son; for the idea of their coming safely back never occurred to him, his knowledge of engines being limited. A loud ring at the bell brought Mrs. Pecq, who was guarding the house, while Mrs. Minot entertained a parlor full of company.

"Frank's run off with No. 11, and he'll be killed sure. Thought I'd come up and tell you," stammered Joe, all out of breath and looking wild.

He got no further, for Mrs. Pecq clapped one hand over his mouth, caught him by the collar with the other, and hustled him into the ante-room before any one else could hear the bad news.

"Tell me all about it, and don't shout. What's come to the boy?" she demanded, in a tone that reduced Joe to a whisper at once.

"Go right back and see what has happened to him, then come and tell me quietly. I'll wait for you here. I wouldn't have his mother startled for the world," said the good soul, when she knew all.

"Oh, I dar'sn't! I opened the switch as they told me to, and Bill will half kill me when he knows it!" cried Joe, in a panic, as the awful consequences of his deed rose before him, showing both boys mortally injured and several trains wrecked.

"Then take yourself off home and hold your tongue. I'll watch the door, for I won't have any more ridiculous boys tearing in to disturb my lady."

Mrs. Pecq often called this good neighbor "my lady" when speaking of her, for Mrs. Minot was a true gentlewoman, and much pleasanter to live with than the titled mistress had been.

Joe scudded away as if the constable was after him, and presently Frank was seen slowly approaching with an unusually sober face and a pair of very dirty hands.

"Thank heaven, he's safe!" and, softly opening the door, Mrs. Pecq actually hustled the young master into the ante-room as unceremoniously as she had hustled Joe.

"I beg pardon, but the parlor is full of company, and that fool of a Joe came roaring in with a cock-and-bull story that gave me quite a turn. What is it, Mr. Frank?" she asked eagerly, seeing that something was amiss.

He told her in a few words, and she was much relieved to find that no harm had been done.

"Ah, the danger is to come," said Frank, darkly, as be went away to wash his hands and prepare to relate his misdeeds.

It was a very bad quarter of an hour for the poor fellow, who so seldom had any grave faults to confess; but he did it manfully, and his mother was so grateful for the safety of her boy that she found it difficult to be severe enough, and contented herself with forbidding any more visits to the too charming No. 11.

"What do you suppose will be done to me?" asked Frank, on whom the idea of imprisonment had made a deep impression.

"I don't know, dear, but I shall go over to see Mr. Burton right after tea. He will tell us what to do and what to expect. Gus must not suffer for your fault."

"He'll come off clear enough, but Joe must take his share, for if he hadn't opened that confounded switch, no harm would have been done. But when I saw the way clear, I actually couldn't resist going ahead," said Frank, getting excited again at the memory of that blissful moment when he started the engine.

Here Jack came hurrying in, having heard the news, and refused to believe it from any lips but Frank's. When he could no longer doubt, he was so much impressed with the daring of the deed that he had nothing but admiration for his brother, till a sudden thought made him clap his hands and exclaim exultingly, -

"His runaway beats mine all hollow, and now he can't crow over me! Won't that be a comfort? The good boy has got into a scrape. Hooray!"

This was such a droll way of taking it, that they had to laugh; and Frank took his humiliation so meekly that Jack soon fell to comforting him, instead of crowing over him.

Jill thought it a most interesting event; and, when Frank and his mother went over to consult Mr. Burton, she and Jack planned out for the dear culprit a dramatic trial which would have convulsed the soberest of judges. His sentence was ten years' imprisonment, and such heavy fines that the family would have been reduced to beggary but for the sums made by Jill's fancy work and Jack's success as a champion pedestrian.

They found such comfort and amusement in this sensational programme that they were rather disappointed when Frank returned, reporting that a fine would probably be all the penalty exacted, as no harm had been done, and he and Gus were such respectable boys. What would happen to Joe, he could not tell, but he thought a good whipping ought to be added to his share.

Of course, the affair made a stir in the little world of children; and when Frank went to school, feeling that his character for good behavior was forever damaged, he found himself a lion, and was in danger of being spoiled by the admiration of his comrades, who pointed him out with pride as "the fellow who ran off with a steam-engine."

But an interview with Judge Kemble, a fine of twenty-five dollars, and lectures from all the grown people of his acquaintance, prevented him from regarding his escapade as a feat to boast of. He discovered, also, how fickle a thing is public favor, for very soon those who had praised began to tease, and it took all his courage, patience, and pride to carry him through the next week or two. The lads were never tired of alluding to No. 11, giving shrill whistles in his ear, asking if his watch was right, and drawing locomotives on the blackboard whenever they got a chance.

The girls, too, had sly nods and smiles, hints and jokes of a milder sort, which made him color and fume, and once lose his dignity entirely. Molly Loo, who dearly loved to torment the big boys, and dared attack even solemn Frank, left one of Boo's old tin trains on the door-step, directed to "Conductor Minot," who, I regret to say, could not refrain from kicking it into the street, and slamming the door with a bang that shook the house. Shrieks of laughter from wicked Molly and her coadjutor, Grif, greeted this explosion of wrath, which did no good, however, for half an hour later the same cars, all in a heap, were on the steps again, with two headless dolls tumbling out of the cab, and the dilapidated engine labelled, "No. 11 after the collision."

No one ever saw that ruin again, and for days Frank was utterly unconscious of Molly's existence, as propriety forbade his having it out with her as he had with Grif. Then Annette made peace between them, and the approach of the Twenty-second gave the wags something else to think of.

But it was long before Frank forgot that costly prank; for he was a thoughtful boy, who honestly wanted to be good; so he remembered this episode humbly, and whenever he felt the approach of temptation he made the strong will master it, saying to himself "Down brakes!" thus saving the precious freight he carried from many of the accidents which befall us when we try to run our trains without orders, and so often wreck ourselves as well as others.