lly where they connect with the dark regions known
as seas, but Dawes did not see them in their full extent, did not
recognize their peculiar character, and entirely failed to catch sight
of the narrower and more numerous ones which constitute the wonderful
network discovered by the Italian astronomer. Schiaparelli found no less
than sixty canals during his first series of observations in 1877.

Let us note some of the more striking facts about the canals which
Schiaparelli has described. We can not do better than quote his own
words:

"There are on this planet, traversing the continents, long dark lines
which may be designated as _canals_, although we do not yet know what
they are. These lines run from one to another of the somber spots that
are regarded as seas, and form, over the lighter, or continental,
regions a well-defined network. Their arrangement appears to be
invariable and permanent; at least, as far as I can judge from four and
a half years of observation. Nevertheless, their aspect and their degree
of visibility are not always the same, and depend upon circumstances
which the present state of our knowledge does not yet permit us to
explain with certainty. In 1879 a great number were seen which were not
visible in 1877, and in 1882 all those which had been seen at former
oppositions were found again, together with new ones. Sometimes these
canals present themselves in the form of shadowy and vague lines, while
on other occasions they are clear and precise, like a trace drawn with a
pen. In general they are traced upon the sphere like the lines of great
circles; a few show a sensible lateral curvature. They cross one another
obliquely, or at right angles. They have a breadth of two degrees, or
120 kilometres [74 miles], and several extend over a length of eighty
degrees, or 4,800 kilometres [nearly 3,000 miles]. Their tint is very
nearly the same as that of the seas, usually a little lighter. Every
canal terminates at both its extremities in a sea, or in another canal;
there is not a single example of one coming to an end in the midst of
dry land.

"This is not all. In certain seasons these canals become double. This
phenomenon seems to appear at a determinate epoch, and to be produced
simultaneously over the entire surface of the planet's continents. There
was no indication of it in 1877, during the weeks that preceded and
followed the summer solstice of that world. A single isolated case
presented itsel