civilised world, as that was; and though apparently a
perfect calm reigned throughout the air-ship, the issue of the
embassy was awaited with the most intense anxiety.

Another half hour passed, and hardly a word was spoken on the deck of
the _Ithuriel_, hanging there in mid-air over the mighty Russian
host, and in range of the field-glasses of the outposts of the German
army of Berlin lying some ten or twelve miles away to the westward.

It was the calm before the threatening storm,--a storm which in less
than an hour might break in a hail of death and destruction from the
sky, and turn the fields of earth into a volcano of shot and flame.
Certainly the fate of an empire, and perhaps of Europe, or indeed the
world, hung in the balance over that field of possible carnage.

If the Russians regained their war-balloons and were left to
themselves, nothing that the heroic Germans could do would be likely
to save Berlin from the fate that had overwhelmed Strassburg and
Metz, Breslau and Thorn.

On the other hand, should the aerostat not return in time with a
satisfactory answer, the victorious career of the Tsar would be cut
short by such a bolt from the skies as had wrecked his fortress at
Kronstadt,--a blow which he could neither guard against nor return,
for it would come from an unassailable vantage point, a little vessel
a hundred feet long floating in the air six thousand feet from the
earth, and looking a mere bright speck amidst the sunlight. She
formed a mark that the most skilful rifle-shot in his army could not
hit once in a thousand shots, and against whose hull of hardened
aluminium, bullets, even if they struck, would simply splash and
scatter, like raindrops on a rock.

The remaining minutes of the last half hour were slipping away one by
one, and still no sign came from the earth. The aerostat remained
moored near the building surmounted by the Russian standard, and the
white flag, which, according to arrangement, had been hauled down to
be re-hoisted if the answer of the Tsar was favourable, was still
invisible. When only ten minutes of the allotted time were left,
Arnold, moving his glass from his eyes, and looking at his watch,
said to Natas--

"Ten minutes more; shall I prepare?"

"Yes," said Natas. "And let the first gun be fired with the first
second of the eleventh minute. Destroy the aerostats first and then
the batteries of artillery. After that send a shell into Frankfort,
if you have a gun