"Indeed he is. We'll soon be back with you and tell you all about it.
Everything is working perfectly. Good-bye, Betty!"
And Mr. Giddings arose with a pleased laugh, and hung up the helmet. "I'll take off my hat to you, Robert," he said. "I never thought your fussing at home all these years with electric batteries, buzzers, and what not, would amount to anything like this."
The Sky-Bird II was now running straight ahead with the speed of the wind, John giving the craft more and more gas, and crowding her pretty close to the limit. The wind swept by both sides of the streamlike cabin with a rushing sound like the distant roar of a huge cataract; the flexible window glass gave slightly to its pressure, but there was no sign of it breaking. One minute they were in the midst of a cumulus cloud; the next, through it. Now they saw the faint outline of the earth, now sky; now the earth was screened by cloud, but above were the blue heavens.
"Guess how fast we're making it now?" cried John, one eye on the dial which connected with the propeller-shaft.
"A hundred miles," ventured Mr. Giddings.
"Hundred and thirty," guessed Paul and Bob.
"Hundred and eighty," stated the more experienced Tom.
"All too low," said John. "We're going just exactly two hundred and fifty, if this speedometer doesn't lie!"
He now announced that he was going to throw in the idle engine. This was done successfully, and under the extra power they were soon making the remarkable speed of three hundred miles an hour! John then slowed up and disconnected first one motor and then the other, the airplane continuing to fly with unimpaired smoothness.
As a last test, he dropped to a level of three thousand feet, at which time they were considerably north of Albany, and throwing the automatic-pilot into operation calmly removed his hands and feet from every control except the rudder. In this fashion they ran for fifteen or twenty miles on a perfectly even keel, the apparatus automatically working the elevators and ailerons of the craft as various wind currents tended to disturb its equilibrium. At length, John gave a little twist to the rudder, and the way the Sky-Bird began to circle, and to bank of her own accord, was a splendid sight to behold. No hawk, sailing over a barnyard in quest of an unwary fowl, could have performed the trick more beautifully.