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.

Peggy shut off the exhaust, turning the explosions of the cylinder into a
muffler. In almost complete silence they winged upward. Up, up, toward the
fleec