“By Jove; she knows enough not to call a naval officer ‘lieutenant,’” thought the young officer, as, with a bow and a word of thanks, he vanished to equip himself for his aerial excursion.

By the time he was invested in a similar long duster, with weighted seams, and had donned a cap and goggles, the larger of the two aeroplanes, named the Golden Butterfly, was ready for its passengers.  Old Sam and his son, who had dragged it out—­it moved easily on its landing wheels—­stood by, their awe of the big craft showing plainly on their faces.

A section of the fence had been made removable, so as to give the Prescott aeroplanes a free run from their stable to the smooth slope of the meadows beyond.  This was now removed, and Peggy, followed by the young officer, took her place in the chassis.  Peggy made a pretty figure at the steering wheel.

“The first improvement I should like to call your attention to,” she began, in the most business-like tones she could muster up, “is the self-starter.  It works by pneumatic power, and does away with the old-fashioned method of starting an aeroplane by twisting the propeller.”

The girl opened a valve connected with a galvanized tank, with a pressure gauge on top, and pulled back a lever.  Instantly, a hissing sound filled the air.  Then, with a dexterous movement, Peggy threw in the spark and turned on the gasoline which the spark would ignite, thereby causing an explosion in the cylinders.  But first the compressed air had started the motor turning over.  At the right moment Peggy switched on the power and cut off the air.  Instantly there was a roar from the exhausts and blue flames and smoke spouted from the motor.  The aeroplane shook violently.  It would have made an inexperienced person’s teeth chatter.  But both the officer and Peggy were sufficiently familiar with aeroplanes for it not to bother them in the least.

“Magnificent!” cried the young officer enthusiastically, as he saw the ease with which the compressed air attachment set the motor to working.

“It will do away with assistants to start the machine,” he declared the next instant.  “The importance of that in warfare can hardly be overestimated.”

Peggy was too busy to reply.  So far all had gone splendidly.  If only she could carry out the whole test as well!

“Ready?” she asked, flinging back the word over her shoulder to Lieutenant Bradbury.

“All ready!” came in a hearty voice from behind her.

Peggy, with a quick movement, threw in the clutch that started the propeller to whirring.

With a drone like that of a huge night-beetle, or prehistoric thunder-lizard, the machine leaped forward as a race-horse jumps under the raised barrier.

In a blur of blue smoke it skimmed through the gap in the palings.  Out upon the smooth meadowland it shot, roaring and smoking terrifically.  And then, all at once, the jolting motion of the start ceased.  It seemed as if the occupants of the chassis were riding luxuriously over a road paved with the softest of eiderdown.  The sensation was delightful, exhilarating.