“No, Massa Tom, I won’t do nuffin laik dat,” promised Eradicate.  “But, Massa Tom, how much does yo’ ’spect a image laik dat would be worth?”

“Haven’t the least idea, Rad.  Enough, though, to make you rich for the rest of your life.”

“Good land a’ massy!” gasped Eradicate, and he spent several hours trying to do sums in arithmetic on scraps of paper.

“Hurrah!” cried Tom, when, on the morning of the third day of their enforced stay in New York, a letter was sent up to his room by the hotel clerk.

“What’s up?” asked Ned.  “I didn’t know that you sent Mary word that you were here.”

“I didn’t, you old scout!” cried Tom.  “This is from the steamship company, saying that the steamer Maderia, on which we have taken passage for Mexico, will sail to-night at high tide.  That’s the stuff!  At last we’ll really get on our way.”

“Bless my notebook!” cried Mr. Damon.  “I hoped we’d stay at least another day here.  I haven’t seen half enough in the museums.”

“You’ll see stranger things than in any museum when we get to the underground city,” predicted Tom.  “Come on, Ned, we’ll take in a moving picture show, have our last lunch in the big city, and then go aboard.”

So impatient were the travelers to go on board the steamer that they arrived several hours before the time set for sailing.  Many others did the same thing, however, as supper was to be served on the Maderia.

Though it was within a few hours of leaving time there seemed so much to be done, such a lot of cargo to stow away, and so much coal to put into the bunkers, that Tom and the others might well be excused for worrying about whether or not they really would sail.

Big trucks drawn by powerful horses thundered down the long dock.  Immense automobiles laden with boxes, barrels and bales puffed to the loading gangways.  There was the puffing and whistling of the donkey engines as they hoisted into the big holds the goods intended for export.

At the side of the steamer were grimy coal barges, into which was dipped an endless chain of buckets carrying the coal to the bunkers.  Stevadores were running here and there, orders and counter-orders were being given, and the confusion must have been maddening to any one not accustomed to it.

“Bless my walking stick!” exclaimed Mr. Damon.  “We’ll never get off to-night, I’m positive.”

“Dat’s right,” agreed Eradicate.  “Look at all dat coal dey’s got to load in.”

“Oh. they knew how to hustle at the last minute,” said Tom, and so it proved.  Gradually the loading was finished.  The coal barges were emptied and towed away.  Truck after truck departed from the dock empty, having left its load in the interior of the steamer.  One donkey engine after another ceased to puff, and the littered decks were cleared.

“Let’s watch the late-comers get aboard,” suggested Ned to Tom, when they had arranged things in their stateroom.  The two boys and Mr. Damon had a large one to themselves and Eradicate had been assigned a small one not far from them.