particularly rapid one, it had been made in a little less than
three days.

As may be easily imagined, a vessel like this was a very different
craft from the old steamers which used to cross the Atlantic--"ocean
greyhounds" they were called--in the latter part of the nineteenth
century.

It would be out of place here to give a full description of the vessels
which at the period of our story, in 1947, crossed the Atlantic at
an average time of three days, but an idea of their construction
will suffice. Most of these vessels belonged to the class of the
Euterpe-Thalia, and were, in fact, compound marine structures, the two
portions being entirely distinct from each other. The great hull of
each of these vessels contained nothing but its electric engines and its
propelling machinery, with the necessary fuel and adjuncts.

The upper portion of the compound vessel consisted of decks and quarters
for passengers and crew and holds for freight. These were all comprised
within a vast upper hull, which rested upon the lower hull containing
the motive power, the only point of contact being an enormous
ball-and-socket joint. Thus, no matter how much the lower hull might
roll and pitch and toss, the upper hull remained level and comparatively
undisturbed.

Not only were comfort to passengers and security to movable freight
gained by this arrangement of the compound vessel, but it was now
possible to build the lower hull of much less size than had been the
custom in the former days of steamships, when the hull had to be large
enough to contain everything. As the more modern hull held nothing but
the machinery, it was small in comparison with the superincumbent upper
hull, and thus the force of the engine, once needed to propel a vast
mass through the resisting medium of the ocean, was now employed upon a
comparatively small hull, the great body of the vessel meeting with no
resistance except that of the air.

It was not necessary that the two parts of these compound vessels
should always be the same. The upper hulls belonging to one of the
transatlantic lines were generally so constructed that they could be
adjusted to any one of their lower or motive-power hulls. Each hull had
a name of its own, and so the combination name of the entire vessel was
frequently changed.

It was not three o'clock when the Euterpe-Thalia passed through the
Narrows and moved slowly towards her pier on the Long Island side of
the city. The quaranti