Not until they were passing Greenwich did either of the detectives come near Mark, then as he and Dick were standing by the bulwarks, looking at the hospital, Chester strolled across the deck and, pointing to the building as if asking him some question about it, said:

“There is a colored man forward, dressed as a sailor.”

“Is that so?” Mark said. “I see no one aft here who looks suspicious, and I don't think they will try anything till we get to Amsterdam. There was a colored man in a boat watching us as we set sail.”

“I saw him, sir. Can he get to Amsterdam before us?”

“Yes, I have no doubt he can; if he lands at Flushing or Antwerp, and takes a post chaise or a diligence, I should say he could get there twenty-four hours before us. Certainly he could do so if he landed at The Hague, as we have to go a long way round to get into the Zuyder Zee. That is where the real danger will be; still you had better keep a sharp lookout on the man forward.”

No more was said. Mark was not long in getting into conversation with the other passengers aft, and later on strolled forward with Dick, asking the sailors some questions as to what sort of passage they were likely to have, and how the wind suited. The men agreed that unless the wind shifted they would not be likely to make a quick passage.

“The wind is northeasterly,” one of them said. “We can only just lay our course now, and it will be dead against us in some of the reaches. Still, I think we shall manage to make down to sea with only a tack or two, but when we are once fairly out of the river it will be a long leg and a short one, and going up round the Texel it will be dead against us. Except that it would be a bit worse if it had a little more east in it, it is about as foul a wind as we could have, and I don't see any sign of a change, worse luck.”

Presently, moving about among them, he got next to Gibbons.

“I don't think we shall have any trouble on board,” he said; “if there is any, it will be after we have landed. But you can keep an eye on that foreign sailor standing alone there up in the bows.”

“All right, sir; if you like, I can manage to get into a quarrel with him, and can warrant that he won't get out of his berth before it is time to go ashore.”