n
a leedle boad?"

"I should think him an unmitigated ass," retorted the colonel.

"Jusd so. Yed thad is whad the aeronauds have been doing; they have
been drying to make the leedle boad-balloon garry the brobelling bower
of the aerial ship. In other words, they have not made their balloons
large enough."

"Then you think they have not yet reached the practical limit to the
size of a balloon?" asked the colonel.

"They have--very nearly--if balloons are do be made only of silk," was
the reply. "Bud if _navigable_ balloons are to be gonsdrugded,
aeronauds musd durn do other maderials and adobd another form. As I
said before, they musd build a _shib_, and she musd be of sufficiend
size to float in the air and to garry all her eguipments."

"But such an aerial ship would be a veritable _monster_" protested the
colonel.

"Zo are the Adlandic liners of the presend day," quietly answered the
professor.

"Phew!" whistled the colonel. The baronet rose from the divan, flung
away the stump of his cigar, and settled himself to listen, and perhaps
take part in the singular conversation.

"And of what would you build your aerial ship, professor?" asked the
colonel when he had in some measure recovered from his astonishment.

"Of the lighdesd and, ad the zame dime, sdrongesd maderial I gould
find," answered the professor. "Once get the aeronaud to realise thad
greadly ingreased bulk and a differend form are necessary, and id will
nod be long before he will find a suitable building maderial. Iv I were
an aeronaud I should dry medal."

"Metal!" exclaimed the colonel. "Oh, come, professor; now you are
romancing, you know. A ship of metal would never float in the
atmosphere."

"A zimilar remarg was made nod zo very many years ago when id was
suggesded that ocean shibs could be buildt of medal," retorted the
professor. "Yed there are thousands of medal shibs in exisdenze do-day;
and there can be no doubt as do the facd thad they fload. And zo will
an aerial shib. The gread--in facd the _only_ diffiguldy in the madder
is thad air is eight hundred dimes lighder than wader; and an air shib
of given dimensions musd therefore be ad leasd eight hundred dimes
lighder than her ocean sisder do enable her do fload in the atmosphere.
The broblem, then, is this: How are you to gonsdrugt a medal shib, of
given dimensions, sdrong enough do hold dogether and withsdand the shock
of goming do earth, yed of less weighd than her o