According to this theory, the phenomena called canals are simply lines
of vegetation, the real canals being individually too small to be
detected. It may be supposed that from a central supply canal irrigation
ditches are extended for a distance of twenty or thirty miles on each
side, thus producing a strip of fertile soil from forty to sixty miles
wide, and hundreds, or in some cases two or three thousands, of miles in
length.
The water supply being limited, the inhabitants can not undertake to
irrigate the entire surface of the thirsty land, and convenience of
circulation induces them to extend the irrigated areas in the form of
long lines. The surface of Mars, according to Lowell's observation, is
remarkably flat and level, so that no serious obstacle exists to the
extension of the canal system in straight bands as undeviating as arcs
of great circles.
Wherever two or more canals meet, or cross, a rounded dark spot from a
hundred miles, or less, to three hundred miles in diameter, is seen. An
astonishing number of these appear on Mr. Lowell's charts. Occasionally,
as occurs at the singular spot named Lacus Solis, several canals
converging from all points of the compass meet at a central point like
the spokes of a wheel; in other cases, as, for instance, that of the
long canal named Eumenides, with its continuation Orcus, a single
conspicuous line is seen threading a large number of round dark spots,
which present the appearance of a row of beads upon a string.
Pages:
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84