"Get up on that seat on the left-hand side, and hang on," warned Barney, and, as Bob obeyed, he pulled open the throttle.
As the iron monster began to move, puffing and smoking at the task of starting the long train, it seemed to the boy that the noise would deafen him. But he soon forgot it in the absorption of watching the fireman open the doors of the firebox, throw in shovels-full of coals, and then inspect the water and steam gauges.
With the gradual increasing of the speed, the din subsided. Yet a new discomfort took its place. So violently did the engine sway, that Bob was obliged to hang on to the window on his side of the cab to keep from bouncing to the floor.
Watching out the corner of his eye, as he scanned the track ahead, the engineer smiled at the boy's trouble in staying on the seat.
Bob, however, soon adapted himself to the engine's motion, and was finally able to sit without clutching the window-frame.
Noting this, Barney got down, crossed the cab, and putting his mouth close to the boy's ear, asked:
"Like to run the engine awhile?"
"Would I? I should say so!" returned Bob in delight.
Though his reply was inaudible, the expression on his face was eloquent.
"Then, take hold of my arm, so you won't get thrown out. That's the way. Steady, now. Climb on to the seat. Good. Now, put your left hand on that lever. That's what they call the throttle. When you pull it toward you, it increases the speed; to slow down, you push it away from you."