Let us now glance at a series of figures on Plate VI, page 113; their artificial character may be recognized at once. They are all designed for channels or thoroughfares for the transportation of men, merchandise, or water. No. 1 represents a tracing from a railroad map of a county in Illinois. The convergence of lines to common centres, and, in one case, parallel lines may be seen. The length of the region represented is thirty-seven miles. No. 2 is a tracing of streets in a district of Montreal, covering an extent of half a mile. No. 3 is a tracing of a small region near Phoenix, Arizona, showing irrigating canals. The larger ones follow contour lines of the surface; the smaller ones are usually laid out in rectangular form to correspond with the original land sections and sub-sections, the boundary lines of which run north and south, east and west. No. 4 represents the canals converging on Groningen, Holland. No. 5 is a tracing from a hemispherical map of Mars made by Schiaparelli, and No 6 is traced from a photograph of a globe on which Lowell has carefully drawn the canals, oases, etc., of Mars covering a land extent of 7,400 miles. The remarkable artificiality of all these figures must be admitted. The lines on the first four figures are laid out by an intelligence for similar purposes. No. 1 for the conveyance of passengers and freight; No. 2 for the traffic of a city; No. 3 for the conveyance of water; No. 4 for purposes of navigation, and Nos. 5 and 6, according to Lowell's view, for the conveyance of water from melting polar snow caps for irrigation purposes. A simple, rational explanation, as their great width and geodetic precision forbid any other. Let one contemplate these lines of Mars and compare them with the natural cracks on Plate V and he will appreciate the emphatic words of Lowell when he says: "The mere aspect is enough to cause all theories about glaciation, fissures, or surface cracks to die an instant and natural death." Consider any other possible tracing of lines on the face of the Earth as the result of Nature's forces, such as river beds, cañons, chasms, fissures, faults, rifts, precipitous valleys, fiords, the results of sharp folds in the strata, parallel chains of mountains, and none of these lines would be straight, none of them would be of uniform width, and few of them would have the enormous breadth of the Martian lines, they would begin nowhere and, with the exception of the rivers, end nowhere. This definition holds good as the result of natural forces from the microscopic crackle on a dinner plate, to a crack in the Earth's crust fifteen hundred miles long.