newly spaded garden. There stood the giant, Koku, holding aloft in the air, by one hand, the form of the struggling colored man, Eradicat

e. "Ef yo' don't I'll bust yo' wide open, dat's whut I'll do

let you fall!"

y nine feet from the ground, and a fall from that distance would seriously jar Eradicate, if it d

me down, an' I w

sked Koku, for such was the gian

eers!" conceded Eradicate. Then, as he was lowered to the ground

?" asked the

n Eradicate, "but didn't yo'

id," admitte

me help-yes?"

too much for you, Rad," said Tom, gent

n, den me an' Boomerang, we-all gwine to die, dat's all I got to say. I was a-spadin' my part ob de garden, Mas

es so fast!" declared the giant, whose Eng

, that you finished your part before Eradicate d

iant grinned

r. Damon, "Eradicate knows a little more about garde

t!" boasted the colored ma

spading the garden, and you, Koku, can come and help me lift som

heavy Koku not lift

f satisfaction, he fell to work in the mellow soil while Tom led Koku to one of the shops where he set him to liftin

r. "And now, Mr. Damon, I can listen to you. Do y

. Let me tell you what I mean. Now cast your mind back. How many ways are now u

m. "At least there are only two

nd that is the tractor type. The other has the propeller in the rear, and that

ked Tom wi

h! but that is the best name I can think of for it. And, real

e a tractor or pusher ty

is now, Tom, you have to get an aeroplane in pretty speed

ises and keeps aloft, by its speed in the air. As soon as tha

eed of the aeroplane for this, why not depend on the

was trying to get at. "If the propeller didn't move the air

o get the propeller of a boat racing around at the rate of a million revolutions a minute, more or less, before your boat will travel, do

some," ad

" asked Mr. Damon, a

to the blades of the screw,

air to the blades of an airship propell

eroplane propeller many times faster than a boat propeller. It's the density that makes the difference, M

l!" cried the eccentric man. "The difference in density! If air were as dense as water the problem would be solved. And

er slow answer. "You know they have condensed, or compressed,

ve to have a speed of more than seven hundred revolutions a minute. What's that compared to the three to ten thousand revolutions of the propellers now used? The propellers of Damon's Whizzer will be of the pusher type, and will revolve in dense,

enthusiastic. The young inventor gazed at

theory, but how is it goi

I hurried over here. I wanted to tell you when I saw you going off on a trip with Miss Nestor. That

ed propeller in very dense, or in liquid, air, there would be more resistance than in the rarefied atmosphere of the upper regions. And, if this could be don

or two on board the aeroplane, and condense the air as you go along. Th

hat's the whole difficulty-compressing

s machinery needed to condense air to a form approximating water,

ir-condensing machinery you would need," Tom told Mr. Damon. "Besides, if you could surround your propellers with a strat

uid air, and I could shatter the steel with a hammer as easil

hey have not succeeded. To condense air and to carry it about so t

o, Tom?" ask

sure

n's Whizzer goes on the scrap heap before ever it's built. Well, we'll say no more about it. You ought to know

Damon, but I have a

went on the eccentric man, as much delighted over Tom's new pla

ry. I wanted to talk to her-to tell her not to jump out when we had a little accid

ceded Mr. Damon. "But I don't supp

t makes the most noise. And that's what I'm going to do-invent a silent aeroplane. Not because I want so much to talk when I take passengers up in the air, but

k on a silent motor for Uncle Sam. I

turning, the young inventor beheld the form of Mr. Peto