Every chance he could get Rob was on the Hercules. All the other enpincers knew Rob, the grandson of Adolph Kerr, and never sent him anay if they saw him about the engine-house. They trusted him because bis grandfather did. Rob was very proud of tuis. One day. wlien he was alone on the Hercules, two schoolmatei came along. "Graudfather ftway, Hnb y " 'Yes, said Silas, they've left me in charge." "Let us get up tliere, too? "¦ "If I let yon fcllows aboard you'll get into mischief," said Rob. They pronrUed not to touch anything. At lengtli, Rob let tlieiu come up' wliere he was. Very soon, one said: "My uncle niakes enjflnes, so I know a lot about them too. Wouldn't it be fun to set this a-going ju.st a minute! " "llob don't dare start up!'' said the other. "I dare, but I won't ! " "What's the harm asked the other. "l ncle showed me how to reverse the lever." Rob said no, but they kept on hintinK and cóaxmg. By-and-by, Rob peered out to see if anybody was Coming, a Btrange, guilty look on bis face. Tlien there was a familiar sound from the üiiifhty horse; it moved slowly along the sldins. "Thcre, don't I know how to stait t?" cried Rob. The Hercules went taster. It seetned to be Ketting ready tor a race. "Sow we must stop it!" cried Rob. "liiifforeii tVo luvur nillAli f " But the boy had forgotten how. He jumped trom the engine, telling the others to "Come on ! " 80 Rob was alone, and in a sad lix. Pale as death, he tried witli all his strength to do as he had seen his g'randfuther. It Wad useless! He had let loóse a forcé he could uot stop. He too jumpedi throwlpg Wmself the same way tlie engine was roing, and rolled over and and down the buik into the buahes. And nmv Uu-re was a great cry from bilas and Mr. Kerr. With territieiï faces, they chased the Hercules. Tuey were too late to get aboard. The engine bad lelt the siding for the maln road, sped along to a bend, and imappeared, the ground treinbling beueath iis powerful tread. Rob feit that he could never look his graudfather in the face again, He bid till dark. Then he went home. Hls niother was crying. And liis gramlfather? It seemed as if he had grown years older. Bllaa was there too, talkin;; pititully 61 CHe Hercules is f II were ome living creature that had lost its life. "Why, here's Rob," said Silas. "Ye won't have no more fine rides with your Krandatr and me!" They've put us out of a job. Heard how the Hercules got away to-day? Wouldn't be ketched 110 more'n a wild horse of the deseit. lie stove up a coal train and pitched head fust into a pasture ! " Rob was surprised that no one sus pected him. "Anybody killed? " he Whlspercd. "All living," was Silas' queer reply, "eicept you randslr. It pretty pretty nigh finished him? " "Of course he'll get another engine, he's 80 smart," faltered Rob. Then his grandfather spoke In a deep, troubled tone. "Xobody would trust the old man again, Rob. They turned h'mi off with hard words. Oh, it's a cruel ending for the work of a lifetime ! " Tears lilled his eyes; they rushed into Rob's too. He could keep it from his grandfather no longer. He told him all. ''If you'll only forgive me," he sobbed, "and trut me as you used to, l'U never touch au engine again, never I" It added heavily to Mr. Kerr's sorrow to flnd that Rob had caused their misery but he put his arm around him and spoke kindly. "There are many other tliings besides enrincs that get the upper hand if tol ka touches them," he said. "I'd willingly suffer if I thought you'd learn this lesson: Never start anything you can't stop. There's men in this town who'll teil you they started drinkinj: and swearing long ago; and it's runningaway with them HOW just as Hercules did with you. Think of this Rob, when you remember wliat h.ippened to your giandfather's last engine I "