possibility of some other liquid being able to take its place, and that
liquid being as omnipresent there as water is here. Mr. Lowell however
never takes this ground, but bases his whole theory on the fundamental
identity of the substance of the bodies of living organisms wherever
they may exist in the solar system. In the next two chapters I shall
discuss an equally essential condition, that of temperature, which
affords a still more conclusive and even crushing argument against the
suitability of Mars for the existence of organic life.



CHAPTER V.


THE TEMPERATURE OF MARS--MR. LOWELL'S ESTIMATE.

We have now to consider a still more important and fundamental question,
and one which Mr. Lowell does not grapple with in this volume, the
actual temperatures on Mars due to its distance from the sun and the
atmospheric conditions on which he himself lays so much stress. If I am
not greatly mistaken we shall arrive at conclusions on this subject
which are absolutely fatal to the conception of any high form of organic
life being possible on this planet.

_The Problem of Terrestrial Temperatures._

In order that the problem may be understood and its importance
appreciated, it is necessary to explain the now generally accepted
principles as to the causes which determine the temperatures on our
earth, and, presumably, on all other planets whose conditions are not