At the sound of the engineer's voice, our hero, who was following leisurely the crowd to one of the cars, looked in that direction to see the soot-begrimed countenance of his old friend. "Lost, Jockey? Never where you are," replied the youth. "Going up? Jump in here, then. It won't be like riding in a parlor-car, but it will suit you just as well, I'm thinking." Rock showed his willingness by springing quickly into the cab. Railroad companies have a rule forbidding persons to ride with the engineer without permission from the president or superintendent, though at the time we write this matter was not as rigidly looked after as now. Rock, however, who had passed nearly all his young life on the foot-board, would have been deemed an exception to any rule. At least, so thought Jockey Playfair, the veteran "knight of the lever" on the Pen Yan mail and accommodation. But Jockey's usual good-humor had been relegated to the background on that evening, as Rock soon saw. The signal to start was given, and with a full head of steam on, the old engine, trembling and groaning from her pent-up power, began to creep ahead, as if feeling her way along the switches and through the yard, going faster and faster at every revolution of her wheels, until the station-lights faded in the distance, and she plowed boldly into the night. The tall form of the engineer, clothed in greasy overalls and jumper, stood at his post like a grim sentinel on duty, his right hand on the reversing lever, his left on the throttle, while his steely gray eyes peered into the gloom, as if expecting to see spring from the regions of darkness the hosts of danger and death. A drizzling rain was falling, so altogether it was a disagreeable night. "I have a favor to ask of you, Rock," said Gilly, the fireman, as the engine fairly gained her feet and increased her progress at every beat of her piston heart. "I want you to take my place until we get to Trestle Foot. I am used up." "Of course I will," replied Rock, taking the fireman's place. "Is she very hungry to-night?" "Hungry and cross, Rock," said the other. "But I'll risk you to feed her." No engineer who has stood at the lever for any length of time refuses to believe that his trusty servant is without her faults, however he may care for her. She is subject to her ill-moods as well as himself. The engine, so good-natured on his last run, so prompt to obey his will, on this trip is stubborn and hard to manage. He can see no reason for her change of spirit. Her wonderful mechanism is in perfect working order, her groom has arrayed her for a dazzling passage, her fireman has fed her with the best of fuel, the flames dart ardently along her brazen veins, she bounds off like a charger, eager for conquest. Her first spurt over, she falters, sulks. No coaxing can change her mood. In vain her master bestows greatest care upon her; with each effort she grows more sullen.