“We shall leave here with as little delay as possible,” observed Frank.  “I have sent our purser, Manuel, to comply with the custom duties, and secure us a few supplies.  When he comes aboard again we expect to start.”

“It is just as well,” remarked the other, significantly, and seeming to be relieved.  “Because, there is an uneasy feeling in Barranquila just at present.  Agents of the revolutionary junta have been here.  They are very active.  And from secret sources I happen to know that they are aware of the strange cargo you are bringing with you.”

“You must mean our aeroplane, Senor?” remarked Frank, quickly.

“Si, Senor Bird,” the other continued, nodding his head.  “It has become known that the two young Americanos are of the new and wonderful aeronauts, with whom nothing is impossible.  And if you remained here any length of time I fear lest even my government might seek to find some excuse for appropriating your little airship.  The talk is all in that direction now.  Colombia is ripe to take a forward step, and have an aviation corps.”

“Well,” said Frank, “under the circumstances we would seriously object to having our monoplane confiscated now, because upon it we depend wholly in our search.  But I thought you were perhaps about to warn us to look out for these revolutionists while passing up the river.”

“It would be wise, Senor,” observed the amiable Colombian ex-diplomat.  “They have agents here; and I happen to know that one is even now on the wharf, observing.  Possibly he seeks to communicate with some spy who chances to be a member of your crew.  So you see, it must pay you to be always on your guard, and prepared!”

CHAPTER X.

NIPPED IN THE BUD.

“There comes Manuel!” remarked Andy, after they had been nearly an hour talking on the deck of the little power boat.

“Yes,” remarked his cousin, who was also on the watch, “and trailing behind him I can see several native carts containing fruits and new supplies.  Manuel surely means that we shall not go hungry while on the river.”

“Then I shall be going, my friends,” said Senor Jose.  “I have told you all I know.  I have warned you to beware of the revolutionists along the river bank.  I have even given you a hint that to delay longer in Barranquila might endanger your enterprise; since the government is just now very anxious to acquire such wonderful modern agents of warfare, as your aeroplane.  It only remains to shake your hands, both, amigos, and wish you every good fortune your valor deserves.”

They squeezed the hand of the fine old Colombian gentleman with vigor.  Never would Andy forget how he had spoken concerning his interest in the sacred duty that had brought the son of the missing aeronaut to his country.

Frank had given strict orders that none of the crew should go ashore, and also that no strangers be permitted to board the craft while they lay there at the old wooden wharf.