others
whose fame had encircled the world. Each of these men cherished hopes of
wonderful discoveries, along his line of investigation, to be made in
Mars.

An elaborate system of signals had, of course, to be devised for the
control of the squadron. These signals consisted of brilliant electric
lights displayed at night and so controlled that by their means long
sentences and directions could be easily and quickly transmitted.

The day signals consisted partly of brightly colored pennons and flags,
which were to serve only when, shadowed by clouds or other obstructions,
the full sunlight could not fall upon the ship. This could naturally
only occur near the surface of the earth or of another planet.

Once out of the shadow of the earth we should have no more clouds and no
more night until we arrived at Mars. In open space the sun would be
continually shining. It would be perpetual day for us, except as, by
artificial means, we furnished ourselves with darkness for the purpose
of promoting sleep. In this region of perpetual day, then, the signals
were also to be transmitted by flashes of light from mirrors reflecting
the rays of the sun.

Yet this perpetual day would be also, in one sense, a perpetual night.
There would be no more blue sky for us, because without an atmosphere
the sunlight could not be diffused. Objects would be illuminated only on
the side toward the sun. Anything that screened off the direct rays of
sunlight would produce absolute darkness behind it. There would be no
graduation of shadow. The sky would be as black as ink on all sides.

While it was the intention to remain as much as possible within the
cars, yet since it was probable that necessity would arise for
occasionally quitting the interior of the electrical ships, Mr. Edison
had provided for this emergency by inventing an air-tight dress
constructed somewhat after the manner of a diver's suit, but of much
lighter material. Each ship was provided with several of these suits, by
wearing which one could venture outside the ship even when it was beyond
the atmosphere of the earth.

Provision had been made to meet the terrific cold which we knew would be
encountered the moment we had passed beyond the atmosphere--that awful
absolute zero which men had measured by anticipation, but never yet
experienced--by a simple system of producing within the air-tight suits
a temperature sufficiently elevated to counteract the effects of the
frigidity