“Huh! seems to me there would be something doing if you happened to run across Puss Carberry at the other side of the world,” declared Andy.

The race kept up for some time, neither seeming to gain to any appreciable extent.  Of course both boys were keyed up to a state of intense nervousness.  Passing through the air at this fearful speed fully five hundred feet above the ground was surely enough to excite them.  One little accident and they would hardly know enough to give a single shout of horror before the end must rush upon them.  And yet Frank appeared as cool as though sitting beside a camp fire, laying out some contemplated air cruise on paper.

Andy was full of complaints.

“Aw, now, whatever do you suppose those measly old insurrectos want to chase us for in this style?” he growled.  “We’re attending to our private business and not bothering them one little bit.  Why don’t they leave a fellow alone?  Goodness knows we’ve just got trouble enough on our hands without this.”

“I don’t know,” said Frank, reflectively, “but I reckon they either want our monoplane or else believe we’re in the employ of the government, and have been sent up here to spy on their movements.  Anyhow, it seems plain that they mean to make a big effort to get us.”

“Which they won’t, if we know it!” cried Andy.  “But see here, Frank, that chap is nervy, all right, going up with Puss and standing all this racket.  A tenderfoot is generally rattled even with a slow flight.  He seems to be holding out.”

“I’ve been thinking about that,” replied his chum.  “And Andy, it looks to me as if that fellow must know something about aviation.  If I could only glimpse him through the glasses I’d soon tell, for he’d show it by the way he sits there alongside Puss.  A new beginner would be hugging the upright for dear life, and showing all the signs of fear.”

“Yes, I know, because I did that same,” answered Andy, once again raising the binoculars as he twisted his head around.

“How is it?” asked Frank.

“Not much signs of fright about him, as far as I can see,” came the ready reply.

“Then make up your mind he’s been up in an aeroplane before.  Perhaps he’s some French or German, who has thrown his fortunes in with the man who wants to sit in the presidential chair at Bogota, and in his own country he must have seen something of aviation.  Oh, well, it doesn’t make much difference to us.  We just have to keep them at a distance and take our chances.”

“But Frank—­”

“Yes, I know what you’re going to say, Andy; that night will soon be coming swooping down on us.  That’s so, and I’m sorry in one way, for it’s going to be a tough old job finding a suitable place to fold our wings on in the darkness.  But we’re up against it good and hard, you see, and it’s what you might call Hobson’s choice.”

Andy showed more positive signs of anger.