of it during his visit, and he
evidently relies thereon to surprise sooner or later the inventor's
secret. But with what object?

"Thomas Roch!" I exclaim.

My voice seems to strike him, and after gazing at me fixedly for an
instant he averts his eyes quickly.

I take his hand and press it. He withdraws it brusquely and walks
away, without having recognized me, in the direction of Captain Spade
and Engineer Serko.

Does he think of speaking to one or other of these men, and if they
speak to him will he be more reasonable than he was with me, and reply
to them?

At this moment his physiognomy lights up with a gleam of intelligence.
His attention, obviously, has been attracted by the queer progress
of the schooner. He gazes at the masts and the furled sails. Then he
turns back and stops at the place where, if the _Ebba_ were a steamer,
the funnel ought to be, and which in this case ought to be belching
forth a cloud of black smoke.

What appeared so strange to me evidently strikes Thomas Roch as being
strange, too. He cannot explain what I found inexplicable, and, as I
did, he walks aft to see if there is a screw.

On the flanks of the _Ebba_ a shoal of porpoises are sporting.
Swift as is the schooner's course they easily pass her, leaping and
gambolling in their native element with surprising grace and agility.

Thomas Roch pays no attention to them, but leans over the stern.

Engineer Serko and Captain Spade, fearful lest he should fall
overboard, hurry to him and drag him gently, but firmly, away.

I observe from long experience that Roch is a prey to violent
excitement. He turns about and gesticulates, uttering incoherent
phrases the while.

It is plain to me that another fit is coming on, similar to the one he
had in the pavilion of Healthful House on the night we were abducted.
He will have to be seized and carried down to his cabin, and I shall
perhaps be summoned to attend to him.

Meanwhile Engineer Serko and Captain Spade do not lose sight of him
for a moment. They are evidently curious to see what he will do.

After walking towards the mainmast and assuring himself that the sails
are not set, he goes up to it and flinging his arms around it, tries
with all his might to shake it, as though seeking to pull it down.

Finding his efforts futile, he quits it and goes to the foremast,
where the same performance is gone through. He waxes more and more
excited. His vague utterances are followed by i