ve exactly the opposite of what its supporters contend. It
appears to have been quite overlooked that as there are so many
thousands of miles of canals it is utterly impossible to suppose that
the vegetation, which is all that we really see, is continuous and
without breaks. It would indeed be most extraordinary if there were not
very many long stretches of land which, for some natural or utilitarian
reasons, were either bare of vegetation or so sparsely covered as to
appear bare when viewed from the earth through a telescope. Some parts
of the canals in hilly or rocky ground may pass through tunnels, and
thus cause apparent gaps in the lines; or ground may be incapable of
bearing vegetation, or purposely left fallow.

"It would, therefore, be no matter of surprise if more powerful
instruments should, in moments of perfect seeing, reveal numerous
apparent gaps in the lines. So far from proving they were not canals,
such gaps are exactly what we should expect to find in connection with
canals; and the lines would probably appear as irregular light and dark
patches in alignment, because we do not see the canals themselves, but
only the vegetation on the land which they traverse. Probably there are
also many oases yet to be discovered along the canal lines.

"As I have already stated, it was asserted that the double lines were
illusions arising from the causes already mentioned, with the probable
addition of eye-strain and bad focussing. Assuming that the single lines
are, as it is declared, illusions, we are confronted with the
assumption that the doubles are illusions of illusions, and this is more
than I can follow, it seems so improbable.

"Professor Lowell has devoted some sixteen years to close and continuous
observation of Mars whenever it has been in a position to be observed,
and many thousands of drawings have been made, the results being plotted
down on a globe. In reply to the statements of occasional observers that
the lines cannot be seen, he testifies that they are not difficult to
see; and that any one who saw them in his exceptionally good atmosphere,
and through his instruments, could have no doubt of their actuality. He
rather caustically, but very justly, remarks in one of his books that
his many years of personal experience in viewing these lines almost
entitle him to an opinion on the subject equal to those who have had
none at all!

"The proof of their existence, however, no longer rests only on t