at by their means long
sentences and directions could be easily and quickly transmitted.

A Novel Signal System.

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 should not fall upon the ships. 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.

Perpetual Night!

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 car even when it was beyond the atmosphere of the earth.

Terrific Cold Anticipated.

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 without. By means of long, flexible tubes, air could be
continually supplied to the wearers of the suits, and by an ingenious
contrivance a store of compressed air sufficient to last for several hours
was provided for each suit, so that in case of necessity the we