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In numerous places elsewhere, Mr Lowell insists further upon the perfect regularity of the lines, the «canals», and the perfect circularity of the spots, the «oases». «So far as it is possible to make out, there is no perceptible difference in width of a canal, when fully developed, from one end of it to the other. Certainly it takes a well-ruled line on paper to look its peer for regularity and deportment». («Mars as the Abode of Life», page 149).
And Mr Lowell takes the regularity of the lines, and the circularity of the spots, as proof that both the one and the other are artificial; the designed work of intelligent craftsmen: «That the lines should follow arcs of great circles, whatever their direction, is as unnatural from a natural standpoint as it would be natural from an artificial one; for the arc of a great circle is the shortest distance from one point upon the surface of a sphere to another. It would therefore, if topographically possible, be the course to take to conduct water, with the least expenditure of time or trouble, from the one to the other. The circular shape of the oases is as directly economic as is the straightness of the canals; for the circle is the figure which incloses the maximun area for the minimum average distance from its centre to any point situated within it. In consequence if a certain amount of country were to be irrigated, intelligence would suggest the circular form in preference to all others, in order thus to cover the greatest space with the least labor». («Mars», page 187).
There have been two entirely different controversies as to the «canals» of Mars. The first arose immediately on the publication of Schiaparelli’s 1877 observations. Several astronomers of great skill and experience had observed the planet during that opposition without detecting the network which Schiaparelli had revealed, and it was natural that they should display a certain reluctance in accepting results so novel and