No, unless something unexpected happened to disturb the plans of the fugitive yeggmen inside the next half hour, they plainly meant to launch out on a voyage across the lake, possibly thousands of feet above its surface, and perhaps among the very clouds.

Not once did Andy dream of asking his cousin whether in this event he considered it the part of wisdom for them to follow the men who were doubly risking their lives in this mad effort to escape with their booty.

He knew Frank only too well to doubt his willingness to undertake such a trip as this.  In times gone by, and especially when they were down in South America with their aeroplane, seeking Professor Bird, who had been lost, with the balloon in which he was conducting experiments on the isthmus, they had bravely faced just as serious perils as this promised to be; yes, and wrenched victory from the jaws of apparent defeat more than once.

Hence, it was a foregone conclusion that if Casper Blue attempted the difficult feat of flying across the lake, after being in the air several long hours, the two Bird boys were determined to keep following after him.  It seemed like a game of “conquer,” which Andy remembered so well; where the rival aviator dared to go they must follow, or acknowledge his superiority as a bold airman, something neither of them felt like doing.

Frank had figured it all out while he was speeding along so smoothly.

So far as he could see everything was working as easily as could be; the motor never missed, and was running like a charm, just as though it could keep this up everlastingly in an endurance test.  And besides, the wind, what there was of it at present, seemed to favor them most positively, because it was at their backs.

So far as appearances went the conditions were ideal for the crossing of the great lake that was now showing up ahead most grandly.

Andy drew in big breaths, and tried to keep from quivering with delight, mingled with just a little nervousness.  Here was a new experience about to come to them; and one that they were not apt to soon forget.  As a boy Andy delighted in novel sensations; and as an ambitious aviator he yearned to experience all the glorious possibilities that open up to the one who has the pluck and the nerve to attempt them.

They could see a town in plain sight, though they had gradually ascended since Andy cast his bomb so successfully.  Perhaps his little game of opening communications with the earth below had been observed by one of those in the leading airship; and in order to prevent another attempt, this gradual ascent had been immediately carried out.

But Frank fully expected to see the rival aeroplane begin to drop as they drew near the border of the fresh water sea.  Since just then there was no squally wind near the surface of the water, which they wished to avoid by remaining thousands of feet high, the chances were that Casper Blue would soon commence to use his deflecting rudder, and begin to descend in wide spirals; or else, with the daring of an old and skilled air navigator, shut off power, and volplane down in a slant that would thrill any spectator as nothing else could, until the required distance had been covered, when he would again bring the shooting aeroplane on a level basis, and resume his forward progress.