All the midshipmen went down the first ladder in silence. Dan, who had preceded the others, crossed the grating and found the second ladder. Once more these youngsters descended. Pennington, as though by mere accident, succeeded in following Dave Darrin down the ladder. Just as they were near the bottom Dave felt a foot descend upon his shoulder, almost with a kick, and then rest there with a crushing pressure. It hurt keenly until Darrin was able to dodge out from under and hurriedly reach the bottom. "Pardon, whoever you are," came a gruff voice. Dave, with his shoulder crippled a good deal, and paining keenly, halted as soon as his foot had touched bottom. It was dark down there, though some reflected light came from an incandescent light at a distance. Dave waited, to peer into the face of the man who had stepped on his shoulder. It was Pennington, of course! "I'll take pains not to go down ahead of you again, or to follow you up a ladder," grunted Darrin suspiciously. "Oh, are you the man on whose shoulder my foot rested?" asked Pennington, with apparent curiosity. "Didn't you know it!" questioned Darrin, looking straight into the other's eyes. Instead of answering intelligibly, Pennington turned and walked away a few feet. "Perhaps that fellow thinks he's going to vent his spite on me in a lot of petty ways," murmured Dave. "If that is the idea he has in his head, he's going to wake up one of these days!" Following the last midshipman came Lieutenant-Commander Forman. "After me, gentlemen," directed the chief engineer. He turned down a narrow passage, only a few feet long, and came out in the furnace room. Here huge fires glowed through the furnace doors. Four of the Navy's firemen stood resting on their shovels. Instantly, on perceiving the chief engineer, however, the men stood at attention. "Pass the word for the chief water tender," ordered the engineer, turning to one of the firemen. The messenger soon came back with a pleasant-faced, stalwart man of forty. "Heistand," ordered the chief engineer, "give these members of the first section, third: class, steam instruction, a thorough drill in firing." "Aye, aye, sir," replied the chief water tender, saluting. "Heistand's orders are mine, Mr. Dalzell," continued the lieutenant-commander, facing Dan. "Preserve order in your section." "Aye, aye, sir," replied Dan, saluting. Acknowledging this courtesy in kind, the chief engineer turned and left the furnace room. Heistand was presumably of German parentage, though he had no accent. He struck the midshipmen as being a pleasant, wholesome fellow, though the water tenders and firemen of the "Massachusetts" knew that he could be extremely strict and grim at need. "You will now, young gentlemen," began Heistand, "proceed to learn all about priming a furnace, lighting, building, cleaning and generally taking care of a fire. Two furnaces have been left idle for this instruction."