Then Robur continued.

"Citizens of the United States, my experiment is finished; but my
advice to those present is to be premature in nothing, not even in
progress. It is evolution and not revolution that we should seek. In
a word, we must not be before our time. I have come too soon today to
withstand such contradictory and divided interests as yours. Nations
are not yet fit for union.

"I go, then; and I take my secret with me. But it will not be lost to
humanity. It will belong to you the day you are educated enough to
profit by it and wise enough not to abuse it. Citizens of the United
States--Good-by!"

And the "Albatross," beating the air with her seventy-four screws,
and driven by her propellers, shot off towards the east amid a
tempest of cheers.

The two colleagues, profoundly humiliated, and through them the whole
Weldon Institute, did the only thing they could. They went home.

And the crowd by a sudden change of front greeted them with
particularly keen sarcasms, and, at their expense, are sarcastic
still.

And now, who is this Robur? Shall we ever know?

We know today. Robur is the science of the future. Perhaps the
science of tomorrow. Certainly the science that will come!