Uptilting the planes caused it to leave the ground and start to curve gracefully upward, as the whizzing propeller did its noisy duty.

They could hear the farmer and his hired hand shouting themselves hoarse with delight at having actually witnessed the start of a modern aeroplane; but naturally the sound grew fainter and fainter in their ears as they left the field and the squatty farmhouse far behind.

Having arisen to the height of several hundred feet, Frank headed toward Bloomsbury.  Like a true and alert pilot he was watching and listening to ascertain how their recent work held; and presently a satisfied expression crossing his face announced that he found his faith well justified.

They had skimmed along for perhaps a mile or more when Andy made a certain discovery that caused him to call out.

“Look along the road below and ahead, Frank,” he said, “and you’ll see something that makes you think of old times, when we hunted, in company with Chief Waller, for those men who looted Leffingwell’s jewelry establishment.”

“Why, as sure as you’re born, Andy, it does look like the Chief; and he’s sitting in a vehicle, waving his hat.  He seems to be looking up at us, and now that I’ve turned off the motor to glide a little I can hear him shouting.”

“Frank, do you think he’s just saluting us, or does he want us to come down?” demanded Andy, in some apprehension.

“Now he’s making all sorts of gestures, and honestly I think he means that he wants to see us.  Had we better drop in that open field just alongside the road?  Looks good to me for a rise when we want to start again.”

“Whatever you think best, Frank; I’m always willing to be guided by you.  Mighty seldom you make a bad mess of it, while I often do.  Yes, let’s drop down, and if the field turns out to be pretty smooth, we’ll land.”

Accordingly, the hydroplane which was of course now in a condition for making a landing with the wheels below the aluminum pontoons, circled around, dropping lower and lower, until presently it came to a stop in the field close to the fence.

When it landed it was done so beautifully that, as Andy enthusiastically said, an egg would hardly have broken had it come between.  And there, not more than twenty feet away, the man, dressed in a blue uniform and wearing a silver shield with the words “Chief of Police” engraved upon it, was soothing his horse, which had apparently been badly frightened by the swooping down of what seemed to be a great roc, or some other species of now extinct gigantic kings of the air.

“What’s up, Chief?” asked Frank, as soon as they had reached the road together.

“Then you haven’t heard the terrible news; they told me you left home to come up here about daybreak; and we didn’t find it out until an hour ago.  The bank in Bloomsbury was broken open last night, the safe rifled, and the thieves have disappeared in the queerest way ever heard of, for they left no trace behind.  And when I saw you boys aloft, I was in hopes you might have seen something of the bank looters.”