SCniAPARELLl's LATEST VIEWS REGARDING MARS. 125 



tbeir outlines become doubtful and ill defined, it is fair to suppose that 

 the water is getting low or is even entirely dried up. Then, in place 

 of the canals there remains either nothing or at most stripes of yellowish 

 color differing little from the surrounding background. Sometimes 

 they take on a nebulous ai)pearance, for which at i)resent it is not pos- 

 sible to assign a reason. At other times true enlargements are produced, 

 expanding to 100, 200 or more kilometers (60 to 120 miles) m breadth, 

 and this sometimes happens for canals very far from the north pole, 

 according to laws which are unknown. This occurred in Hydaspes 

 in 1864, in Simois in 1879, in Ackeron in 1884, and in Triton in 1888. 

 The diligent and minute study of the transformations of each canal 

 may lead later to a knowledge of the causes of these efifcts. 



But the most surprising phenomenon pertaining to the canals of Mars 

 is their gemination, which seems to occur principally in the months 

 which prece<le and in those which follow the great northern inunda- 

 tion — at about the times of the equinoxes. In consequence of a rapid 

 process, which certainly lasts at most a few days, or even perhaps, 

 only a few hours, and of which it has not yet been possible to determine 

 the particulars with certainty, a given canal changes its appearance 

 and is found transformed through all its length into two lines or uni- 

 form stripes more or less parallel to one another, and which run straight 

 and equal with the exact geometrical precision of the two rails of a rail- 

 road. But this exact course is the only point of resemblance with the 

 rails, because in dimensions there is no comparison possible, as it is 

 easy to imagine. The two lines follow very nearly the direction of the 

 original canal and end in the place where it ended. One of these is 

 often superposed as exactly as possible upon the former line, the other 

 being drawn anew; but in this case the original line loses all the small 

 irregularities and curvature that it may have originally possessed. 

 But it also happens that both the lines may occupy opposite sides of 

 the former canal and be located upon entirely new ground. The dis- 

 tance between the two lines differs in different geminations and varies 

 from 600 kih)meters (360 miles) and more down to the smallest limit at 

 which two lines may api)ear separated in large visual telescopes — less 

 than an interval of 50 kilometers (30 miles). The breadth of the stripes 

 themselves may range from the limit of visibility, which we may sup- 

 pose to be 30 kilometers (18 miles), up to more than 100 kilometers (60 

 miles). The color of the two lines varies from black to a light red, 

 which can hardly be distinguished from the general yellow background 

 of the continental surface. The space between is for the most part 

 yellow, but in many cases appears whitish. The gemination is not nec- 

 essarily confined only to the canals, but tends to be produced also in 

 the lakes. Often one of these is seen transformed into two short, broad, 

 dark lines parallel to one another and traversed by a yellow line. In 

 these cases the gemination is naturally short and does not exceed the 

 limits of the original lake. 



