consists
simply of four long sticks arranged in a square, with one third of the
length at either end covered with a specially treated and tightly
stretched muslin."

He was working rapidly as he talked, and, before long the kite was
assembled, the wire attached and wound on the reel and all was ready for
launching.

"Will that wire hold it, sir?" asked Ross, as he noted the extremely
fine line that the Forecaster was using.

"Certainly, it's piano wire. It's only a thirty-second part of an inch
in diameter, but it will stand a pull of nearly three hundred pounds.
That's more than you could pull. More even than Monroe could pull, and
he's the strongest of you."

"Couldn't I hold one of those small kites, sir?" asked Monroe.

"Yes," the Forecaster said, "you could with a well-made hand reel, and
if the wind wasn't too strong. But your arms would soon give out. Of
course, the pull of a kite depends on the amount of square feet of sail
area. Anton," he added, turning to the crippled lad, "you're the
mathematician of the League, measure that kite and tell us how many
square feet of sail area it has."

Anton took a foot rule from his pocket and measured the kite rapidly.

"A trifle over thirty-six feet, sir," he said. "I can give you the
fractions, if you like."

"No, that's near enough," said the Forecaster. "Thirty-six feet of sail
area in a fourteen mile wind will lift nearly twenty pounds of wire and,
probably, will have a pull of about sixty pounds. I don't think you'd
care to stand a sixty-pound drag very long, Monroe. We'll let our new
reel do the work."

"About how high could we make this kite go, sir?" asked Tom. "Does that
depend on the wind?"

"No," the Forecaster answered, "it depends on the sail area of the kite
and the weight of the wire. Ten square feet of sail area will lift three
pounds or, a thousand feet of wire. There are over five thousand feet to
a mile, and a kite usually ascends at about an angle of forty-five
degrees. So, if you allow for sag and so forth, you'd have to put out
eight or nine thousand feet of wire to reach a mile, wouldn't you?"

"Yes," said Tom, "I guess that's how it would go."

"It's an awful lot of line," commented Fred.

"Therefore," said the Forecaster, "if ten square feet will lift a
thousand feet of wire, for eight thousand feet, you'd need eighty
square feet of sail area."

"Then even the two of these together aren't big enough to go up a mile!"
cried Tom.