success, and we are now in sight of further advances that will
enable a traveller in a high latitude moving west to keep pace
with the sun, and, should he wish it, to have unending day."



CHAPTER V.

DR. CORTLANDT'S HISTORY CONTINUED.

"In marine transportation we have two methods, one for freight
and another for passengers. The old-fashioned deeply immersed
ship has not changed radically from the steam and sailing vessels
of the last century, except that electricity has superseded all
other motive powers. Steamers gradually passed through the five
hundred-, six hundred-, and seven hundred-foot-long class, with
other dimensions in proportion, till their length exceeded one
thousand feet. These were very fast ships, crossing the Atlantic
in four and a half days, and were almost as steady as houses, in
even the roughest weather.

"Ships at this period of their development had also passed
through the twin and triple screw stage to the quadruple, all
four together developing one hundred and forty thousand indicated
horse-power, and being driven by steam. This, of course,
involved sacrificing the best part of the ship to her engines,
and a very heavy idle investment while in port. Storage
batteries, with plates composed of lead or iron, constantly
increasing in size, had reached a fair state of development by
the close of the nineteenth century.