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148 In the region visible at this opposition Schiaparelli has 79 canals. Of these 67 appear in the list given above. Of the other 12, the majority lie north of the equator, and therefore were likely not to be as visible as the rest at this last opposition, for two reasons connected with their position: first, on account of the tilt of the planet's axis at the time; and, secondly, because their northern situation would make their development late, as we shall shortly see. As no attempt was made to identify Schiaparelli's list, it will be seen how close is the accordance.

Of the 116 canals not down on Schiaparelli's map, 44 are canals in the dark regions and 72 canals in the light ones. Some of these, too, he saw prior to 1894. Both sets are, as a rule, more difficult of detection than the ones on his map; although there are some exceptions, attributable probably to difficulty of identification. The Brontes and Steropes, for example, might, unless well seen, be confounded with the Gigas on the one hand, or the Titan on the other. The most peculiar case, however, is the relative conspicuousness of the Ulysses.

It is patent that here are phenomena that are passing strange. To read their riddle we had best begin by excluding what they are not, as help towards deciphering what they are.