"And it is not dear," said Uncle Prudent, as he handed to the
inventor in return for his formal receipt the last installment of the
hundred thousand paper dollars he had paid for his invention.

Immediately the Weldon Institute set to work. When there comes along
a project of practical utility the money leaps nimbly enough from
American pockets. The funds flowed in even without its being
necessary to form a syndicate. Three hundred thousand dollars came
into the club's account at the first appeal. The work began under the
superintendence of the most celebrated aeronaut of the United States,
Harry W. Tinder, immortalized by three of his ascents out of a
thousand, one in which he rose to a height of twelve thousand yards,
higher than Gay Lussac, Coxwell, Sivet, Croce-Spinelli, Tissandier,
Glaisher; another in which he had crossed America from New York to
San Francisco, exceeding by many hundred leagues the journeys of
Nadar, Godard, and others, to say nothing of that of John Wise, who
accomplished eleven hundred and fifty miles from St. Louis to
Jefferson county; the third, which ended in a frightful fall from
fifteen hundred feet at the cost of a slight sprain in the right
thumb, while the less fortunate Pilatre de Rozier fell only seven
hundred feet, and yet killed himself on the spot!

At the time this story begins the Weldon institute had got their work
well in hand. In the Turner yard at Philadelphia there reposed an
enormous aerostat, whose strength had been tried by highly compressed
air. It well merited the name of the monster balloon.

How large was Nadar's Geant? Six thousand cubic meters. How large was
John Wise's balloon? Twenty thousand cubic meters. How large was the
Giffard balloon at the 1878 Exhibition? Twenty-five thousand cubic