Of all this Spike appeared to be fully aware, for he quitted the work several times before it was finished, in order to take a look at the stranger, and at the land.  When the batteries were arranged, he and Mulford, each provided with a glass, gave a few minutes to a more deliberate examination of the first.

“That’s the Mona ahead of us,” said the captain; “of that there can be no question, and a very pretty land-fall you’ve made of it, Harry.  I’ll allow you to be as good a navigator as floats.”

“Nevertheless, sir, you have not seen fit to let me know whither the brig is really bound this voyage.”

“No matter for that, young man—­no matter, as yet.  All in good time.  When I tell you to lay your course for the Mona, you can lay your course for the Mona; and, as soon as we are through the passage, I’ll let you know what is wanted next—­if that bloody chap, who is nearing us, will let me.”

“And why should any vessel wish to molest us on our passage, Captain Spike?”

“Why, sure enough!  It’s war-times, you know, and war-times always bring trouble to the trader—­though it sometimes brings profit, too.”

As Spike concluded, he gave his mate a knowing wink, which the other understood to mean that he expected himself some of the unusual profit to which he alluded.  Mulford did not relish this secret communication, for the past had induced him to suspect the character of the trade in which his commander was accustomed to engage.  Without making any sort of reply, or encouraging the confidence by even a smile, he levelled his glass at the stranger, as did Spike, the instant he ceased to grin.

“That’s one of Uncle Sam’s fellows!” exclaimed the captain, dropping the glass.  “I’d swear to the chap in any admiralty court on ’arth.”

“’T is a vessel of war, out of all doubt,” returned the mate, “and under a cloud of canvas.  I can make out the heads of her courses now, and see that she is carrying hard, for a craft that is almost close-hauled.”

“Ay, ay; no merchantmen keeps his light stun’-sails set, as near the wind as that fellow’s going.  He’s a big chap, too—­a frigate, at least, by his canvas.”

“I do not know, sir—­they build such heavy corvettes now-a-days, that I should rather take her for one of them.  They tell me ships are now sent to sea which mount only two-and-twenty guns, but which measure quite a thousand tons.”

“With thunderin’ batteries, of course.”

“With short thirty-twos and a few rapping sixty-eight Paixhans—­or Columbiads, as they ought in justice to be called.”

“And you think this chap likely to be a craft of that sort?”

“Nothing is more probable, sir.  Government has several, and, since this war has commenced, it has been sending off cruiser after cruiser into the Gulf.  The Mexicans dare not send a vessel of war to sea, which would be sending them to Norfolk, or New York, at once; but no one can say when they may begin to make a prey of our commerce.”