Then came other shots, many of them, and the air seemed full of strange hissing sounds.  Twice Frank felt a slight shock that told him some part of the aeroplane had been struck by one of the flying missiles.  His heart seemed to jump almost into his mouth, as he trembled for the result.  But nothing happened.  The motor kept up its insistent humming, and there was not a quiver to indicate that a vital part of the monoplane had been injured.

“Andy, are you hurt?” he called, after the volley had ceased, the marksmen below having evidently exhausted their ammunition.

“Only a scratch,” came the reply.  “Hardly drew blood.  Think a splinter from the wood where a spent bullet zipped past must have hit me.  It’s all right, Frank!  We ran the gantlet just fine.  But all the same I guess it would be better for us to keep a little higher after this.”

“Did you make them out and were they government troops, do you think?” Frank asked, for though he managed to turn his head, already had they made such speed that only the interminable forest could be seen in their rear.

“No,” returned his comrade.  “I just reckon it was another camp of these insurrectos.  You remember the senor said there were apt to be more than one crowd of them up the river.  It’s the only way to get in and out of this country, and everything that happens has to count on a water route.  I guess the Magdalena is about the same to this part of Colombia that the old Nile is to all Egypt.”

“Well, it was a narrow escape, all right,” Frank declared.  “I don’t just like the sound of those bullets all around when you’re six or eight hundred feet up in the air.”

Andy had recovered from his recent fright by now and could even laugh.

“I should say nix,” he observed; “especially when you know that one little clip on either wing would upset us like a stone.  Excuse me, if you please.  I’ll never be fully happy when flying until we invent some sort of little parachute that in case of a drop will give a fellow a chance for his money.”

Another hour passed, when Frank declared they had now reached the point where a descent would be advisable in case they found an opening that looked suitable.

“There are the mountains over yonder on the right,” he said, “and from now on we had better begin to scour the country, covering every mile just as though we had a comb and meant to explore it all.”

The chance to drop came presently, and as the opening proved everything they could desire, a landing was made without the least trouble.  Here they rested and partook of a light lunch, having brought plenty of provisions along, together with a gun of the latest repeating type, with which Colonel Josiah had presented them.

Frank, upon looking the aeroplane over a little later, discovered that he had been wise in deciding to make a halt.  There was need of some attention.  Certain parts had become weakened by the strain, either in the long voyage and handling on board the steamer, or else in this new flight.