It was the first word that had passed between them since the mishap at the siding, but many a grateful glance had the young engineer cast at his helper. It seemed as if the shake-up at Plympton had shaken all the nonsense out of Lemuel Fogg. Before that it had been evident to Ralph that the fireman was doing all he could to queer the run. He had been slow in firing and then had choked the furnace. His movements had been suspicious and then alarming to Ralph, but since leaving Plympton he had acted like a different person. Ralph knew from practical experience what good firing was, and he had to admit that Fogg had outdone himself in the splendid run of the last one hundred miles. He was therefore fully in earnest when he enthusiastically designated his erratic helper as a "brick." It was hard for Fogg to come out from his grumpiness and cross-grained malice quickly. Half resentful, half shamed, he cast a furtive, sullen look at Ralph. "Humph!" he muttered, "it isn't any brick that did it--it was the briquettes." "The what, Mr. Fogg?" inquired Ralph. "Them," and with contemptuous indifference Fogg pointed to a coarse sack lying among the coal. "New-fangled fuel. Master mechanic wanted to make a test." "Why, yes, I heard about that," said Ralph quickly. "Look like baseballs. Full of pitch, oil and sulphur, I understand. They say they urge up the fire." "They do, they burn like powder. They are great steam makers, and no question," observed Fogg. "Won't do for a regular thing, though." "No?" insinuated Ralph attentively, glad to rouse his grouchy helper from his morose mood. "Not a bit of it." "Why not?" "Used right along, they'd burn out any crown sheet. What's more, wait till you come to clean up--the whole furnace will be choked with cinders." "I see," nodded Ralph, and just then they rounded near Macon for a fifteen minutes wait. As Fogg went outside with oil can and waste roll, Mervin Clark came into the cab. "Glad to get back where it's home like," he sang out in his chirp, brisk way. "Say, Engineer Fairbanks, that monument of brass buttons and gold cap braid is the limit. Discipline? why, he works on springs and you have to touch a button to make him act. I had to chum with the brakeman to find out what's up." "Something is up, then?" inquired Ralph a trifle uneasily. "Oh, quite. The conductor has been writing a ten-page report on the collision. It's funny, but the station man at Plympton----" "New man, isn't he?" inquired Ralph. "Just transferred to Plympton yesterday mornin'," explained Clark. "Well, he swears that your front signals were special at the curves and flashed green just as you neared the semaphore." "Absurd!" exclaimed Ralph.