"We'll take it back to the _Rambler_," Captain Joe said. "Perhaps we can find a way to open it there."

"We'll find a way to open it," Alex exclaimed, "when we get hold of the doc.u.ment Max was looking for in the cabin of the _Cartier_."

"Good idea!" Captain Joe replied. "If you wait long enough, you'll always find something like intelligence in the head of a boy!"

When the party returned to the cabin, daylight was just showing in the east and the noisy revel of those at the campfire had ceased.

"I tell you what it is," Captain Joe exclaimed, "those fellows have given up chasing us for the reason that they have arrived at the conclusion that we don't know any more about the lost channel than they do. At first, they doubtless thought the map might direct us to it, but now they have given up that idea, and are satisfied to let us hunt for the lost charter if we want to."

"Yes, but they are still watching us, all the same," Clay replied, "expecting to take the proceeds of the discovery away from us if we are lucky enough to find what both parties are seeking for."

This explanation of Captain Joe's seemed to be the correct one, for the boys were not molested while on their way to the _Rambler_ with the steel box. Having secured the box, the question now was how to get it open, so nearly all that day, they searched among the papers in the cabin of the _Cartier_ for some clue to the mystery. Before night it was found in a bundle of old papers stowed away in a secret draw at the bottom of the owner's secretary, where it had lain for a long time.

"This is easy," Clay said holding the paper up between his thumb and fingers. "The box is only an old French puzzle box. Press on the upper right hand front corner and a b.u.t.ton will show. Press the b.u.t.ton and the box will open, and there you are."

"What the d.i.c.kens do you think the Fontenelles left this paper laying around in a place like this for?" asked Case. "Do you suppose they knew what it was?"

"Of course they knew," Clay answered, "and the paper was brought along so that the box might be opened as soon as found."

Although the hinges and lock of the steel box were rusted, it was opened with little difficulty and there were the family jewels and the lost charter! In spite of difficulties, the boys had succeeded in their quest. The search of more than three hundred years was ended!

When the _Rambler_ and the _Cartier_ started away toward Quebec, they left the men who had opposed them still on the peninsula. Reaching the city, they lost no time in communicating the result of their expedition to the Fontenelles. It is needless to say that the latter were overjoyed at the recovery of the charter and the jewels.

At the close of the interview between the elder Fontenelle and Clay, the former wrote a check for ten thousand dollars and pa.s.sed it over to the boy. Clay smiled as he pa.s.sed it back.

"You remember," he said, "that we recovered the _Cartier_, and that we searched her papers pretty thoroughly to discover the secret of the steel box. Well, Captain Joe, our old friend from Chicago, has conceived a great liking for the boat, and if you can induce your son to give us the launch, and also to make no trouble for the poor people who will suffer under this charter, we shall consider ourselves amply repaid for all our trouble. It has been a pleasant excursion, anyway."

"So far as the boat is concerned," the old man Fontenelle replied, "you are ent.i.tled to it as salvage. Besides, now that the charter and the jewels have been discovered, through your agency, the _Cartier_ will no longer be elaborate enough for my son. He will have a handsome yacht built, anyway, so you may as well take the launch. So far as making trouble for those who have occupied our lands for years goes, no one shall suffer except those who combined their wealth to obstruct us.

"And so you see," he continued, "that the check is yours after all."

And the old gentleman would not accept "No." for an answer.

"One thing I should like to know," Clay said, before leaving Mr.

Fontenelle, "and that concerns the mysterious map we received and the manner in which it came into our possession."

"I can set you right on that point," the old man said. "The man who gave you the map and who was drowned that same night was long in our employ. He finally became angry at some fancied slight and disappeared taking with him valuable papers. It is believed that the crude map delivered to you was among the papers he took. At any rate, on the day before you saw him, he expressed to a relative remorse at what he had done and promised to restore the papers. How he came to deliver the map to you, knowing the _Cartier_ as well as he did, is something which will never be known."

The boys left Quebec the next morning without waiting for the return of the men who were still looking for the lost channel on Cartier island. Therefore they never saw either Lawyer Martin or Max again, but they read later in the news dispatches of Max being sentenced to the penitentiary for highway robbery.

The boys went over the old ground on the river again to Ogdensburg, where the _Cartier_ was fully equipped with new electrical apparatus and then the two started away on their long journey up the lakes.

Captain Joe, was, of course, overjoyed at becoming the owner of the launch, which is now one of the show vessels on the South Branch.

Captain Joe, the bulldog, and Teddy when in Chicago alternate between the _Rambler_ and the _Cartier_, having a welcome on either boat.

The boys were not content to remain long on the South Branch. In fact, within a few days, they fitted the _Rambler_ out for a trip down the Ohio river. What occurred during this trip will be related in the next volume of this series ent.i.tled: The Six River Motor Boat Boys on the Ohio; or, the Three Blue Lights.