tion. But even granting the existence of such, a race of Goliaths on our neighbor world, it is not conceivable that they could have constructed a system of tremendous canals over half the surface of their planet, or that they would have done it if they could. The canals of Mars are enormously disproportioned in magnitude to the most gigantic inhabitants that a due regard for the law of gravitation would suffer us to imagine there.
An ingenious Frenchman has considerately and considerably diminished the difficulty for the inhabitants of Mars by the suggestion that the continents of that planet are so slightly elevated above the level of its seas that frequent and periodical inundations occur over large areas, thus forming temporary channels of communication between the seas which leave only the more elevated points above water to serve as places of refuge for the non-aquatic inhabitants. According to the theory, these inhabitants, possessing a horse sense comparable to that of the descendants of Noah, have, in the course of ages, improved and strengthened their natural places of refuge in times of flood, by excavating the ground from the low lands periodically invaded by the sea, and piling it up on the higher places, thus producing lines of partly artificial hills geometrically placed, and with talus-like flanks.
It will be observed that these attempts at explanation make no reference to the duplication of the canals. Mr. Proctor, always fertile in ingenious theories, undertook to include this strange transformation in an explanation of the canals which he suggested; namely, that they are great rivers, over and along which, in certain seasons, vast fog-banks are formed, or which, perhaps, being frozen in winter, remain covered with snow and ice in spring until the snow is melted along their banks, so that by a phenomenon of diffraction the image of the rivers appears to us as a light line between two dark ones.
M. Fizeau has put forth a theory according to which the canals of Mars are simply glacial productions, enormous crevasses and clefts in the ice covering the planet, like those seen on a smaller scale in our glaciers. But this theory, of course, would imply that Mars is now undergoing the effects of a glacial epoch, involving even the equatorial regions of the planet, while, as a matter of fact, the surface of Mars appears not to suffer from any extreme degree of cold. Attention has also been called to a fancied resemblance between the rectilineal canal system of Mars and the systems of rays seen on the moon, especially that which has. its center at the crater Tycho, and which, under certain illuminations, is one of the most conspicuous features of the lunar surface.
In fact, it may be said, in a double sense, that there is no end of speculations on this curious subject. But nothing has yet been proposed that covers all the appearances presented, and even a
