he doctor, "that the brighter
the light the darker will be the shadow. Now, this projectile is a
perfectly black, non-reflecting object five feet wide. It will cast a
shadow in front of it five hundred feet long. When we are comparatively
near Mars my telescope, situated in the miniature night cast by the
projectile, will find the planet, and we can then steer directly for
him. If we should chance within eighty thousand miles of him, he would
attract us to him in a straight line. But we shall not rely upon chance.
Moreover, when we are as near to him as that, the light and heat of the
Sun's rays will have decreased sixty or seventy per cent. When Mars is
farthest from the Sun, he receives only one-third as much light as the
Earth does. But he is now almost at his nearest point to the Sun, and
receives half as much light."
"Well, you certainly have a pretty clear idea of how to steer the course
all the way, Doctor. And I was hasty enough to think you had overlooked
this entire phase of the subject!" I ejaculated.
"Indeed, I have thought of it very much. And we should not enjoy all
these advantages if we had not started just before opposition. At any
other time the Earth's shadow would not point toward Mars, nor would the
transit of the Earth over the Sun be of any use to us."
"All this reassures me greatly," I replied; "but I shall keep a close
watch from my rear window for danger lights on the Earth."
"It must be time for breakfast," put in the doctor. "Will you see how
tempting a meal you can prepare?"
There was one reservoir built inside the compartments, from which we
drew cool water, and another built next to the outer steel framework,
from which we could draw boiling water. As this tank was connected with
the discharge pipe of the air-pump, and thus with the exterior, I was
disgusted to find that, although the water boiled furiously, and was
rapidly wasting away in steam, it did not become hot enough to make good
beef tea. The heat escaped with the steam at a comparatively low
temperature, so that I was compelled to boil water over my gas jet for
the meat extract, which we drank instead of coffee. I also prepared some
sandwiches of roast beef and cold ham, and with great relish we began
our diet of ready cooked foods, which was to continue for so long.
After this meal I felt quite sleepy, for I had enjoyed but three hours'
rest. The doctor saw my yawns and told me to turn out the gas and have a
long doz
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