ht examine it a little more critically.

The flagship was driven into the smoke cloud so deeply that for a minute
we were again enveloped in night. A quantity of the smoke was entrapped
in a glass jar.

Rising again into the sunlight, the chemists began an examination of the
constitution of the smoke. They were unable to determine its precise
character, but they found that its density was astonishingly slight.
This accounted for the rapidity with which it had risen, and the great
height which it had attained in the comparatively light atmosphere of
Mars.

"It is evident," said one of the chemists, "that this smoke does not
extend down to the surface of the planet. From what the astronomers say
as to the density of the air on Mars, it is probable that a clear space
of at least a mile in height exists between the surface of Mars and the
lower limit of the smoke curtain. Just how deep the latter is we can
only determine by experiment, but it would not be surprising if the
thickness of this great blanket which Mars has thrown around itself
should prove to be a quarter or half a mile."

"Anyhow," said one of the United States army officers, "they have dodged
out of sight, and I don't see why we should not dodge in and get at
them. If there is clear air under the smoke, as you think, why couldn't
the ships dart down through the curtain and come to a close tackle with
the Martians?"

"It would not do at all," said the commander. "We might simply run
ourselves into an ambush. No; we must stay outside, and if possible
fight them from here."

"They can't keep this thing up forever," said the officer. "Perhaps the
smoke will clear off after a while, and then we will have a chance."

"Not much hope of that, I am afraid," said the chemist who had
originally spoken. "This smoke could remain floating in the atmosphere
for weeks, and the only wonder to me is how they ever expect to get rid
of it, when they think their enemies have gone and they want some
sunshine again."

"All that is mere speculation," said Mr. Edison; "let us get at
something practical. We must do one of two things; either attack them
shielded as they are, or wait until the smoke has cleared away. The only
other alternative, that of plunging blindly down through the curtain is
at present not to be thought of."

"I am afraid we couldn't stand a very long siege ourselves," suddenly
remarked the chief commissary of the expedition, who was one of the
members