Having briefly alluded to some of the theories advanced to explain the geodetic network of lines encircling Mars--theories in one case so puerile, and in another case an interpretation so monstrous, though endorsed by astronomers of standing--we turn to the suggestion that these various lines are artificial, that they were designed for a definite purpose, namely, to conduct water from those regions alone where water is found for the purposes of irrigation. We shall call attention to a parallel case where the great ice caps and glaciers of the Himalaya Mountains supply water, by their melting, for thousands of miles of irrigating canals. Let us ask ourselves whether if the snows of the Himalayas gradually failed, the crowded millions of India would not if necessary reach out to the farthest North for this precious fluid? Our great centres of population at the present time are reaching out in every direction for water supply. How long would it take New York City to decide in case of water famine to tap the Great Lakes to the north, or to establish pipe lines to the north pole, if it were necessary to go that distance for water? From the foregoing it is seen that the question of water supply has engaged the energies of man from pre-historic times. These great irrigating works are found, however, in regions of sterility, or light rainfall, from the rude irrigating canals of ancient Peru and Arizona to the marvellous accomplishments of the hydraulic engineer in India and Egypt. This demand for more water is not, however, confined to regions of sterility, the reaching out of cities for supplies of water for potable purposes and for the wasteful disposal of sewage was inevitable. What shall we say, however, of the notes of warning in regions of rain? England is considered a land of humidity and copious rains, and yet the alarm is already sounded that in the no distant future an appalling catastrophe may threaten her in the failure of her water supply. In a special despatch to the "New York Herald," Mr. Bently, president of the Royal Meteorological Society, is quoted as saying at its Annual Meeting, "So enormous now is the drain upon the country's available supplies, so much have the growth of cities, the disappearance of forested areas, the extent of street surface impervious to moisture, and the diversion of the rivers, lakes, and other natural fresh water reservoirs from their natural function of irrigators and distributors of the all essential moisture to the land interfered in England with nature's arrangements, that English engineers and meteorologists at no distant date may find a task of almost insuperable difficulty awaiting their endeavors."