Page Content (OCR)
38 That these two things, straight lines and roundish spots, should, with our present telescopic means, be the sole markings to appear on the vast desert regions of the planet is suggestive in itself. Another significant fact as to the character of either marking is the manifest association of the two. In spite of the great number of the spots, not one of them stands isolate. There is not a single instance of a spot that is not connected by a canal to the rest of the dark areas. This remarkable inability to stand alone shows that the spots and the canals are not unrelated phenomena, for were there no tie between them they must occasionally exist apart. Nor is this all. There is, apparently, no spot that is not joined to the rest of the system, not only by a canal, but by more than one; for though some spots, such as the Fountain of Youth, have appeared at first to be provided with but a single canal connection, later observation has revealed concurrence in the case. The spots are, therefore, not only part and parcel of the canal system, but terminal phenomena of the same. They are, generally speaking, more difficult features to see than the canals. In consequence, they have been among the most recent details to be made out upon the planet's surface. It was not until 1892, at Arequipa, that they were seen in anything like their real numbers. Of them, indeed, are the forty lakes found by Professor W. H. Pickering. This year, at Flagstaff, still others have been discovered, to detection of their character, as I think. In the first place, as I have said, there appears to be no spot that has not two or more canals running to it; in the second place, I find, reversely, that apparently no canal junction is without its spot. Such association is a most tell-tale circumstance. I believe the tule to have no exception. The more prominent junctions all show spots; and with regard to the less conspicuous ones, it is to be remembered that, as the canals are more easy to make out than the spots, the relative invisibility of the latter is to be expected. From which it would seem that the spots are fundamental features of the junctions, and that for a junction to be spotless is, from its very nature, an impossibility. Next to their regularity of position is to be remarked their regularity of form. Their typical shape seems to be circular; for the better the atmosphere, the rounder they look. Under poor seeing they show as irregular patches smooching the disc, much as the canals themselves show as streaks; the spots differing from the canals in being thicker and not so long. As the seeing improves, the patches differentiate themselves into round dots and connecting lines. Such is the shape of the spots associated with single canals; that is, canals not double. In the case of the double canals, the spots look like rectangles with the corners rounded off. One of the most striking of all of them is the Trivium Charontis, reo 1 Otherwise the great reddish-ochre areas are absolutely bare; of that pale fire-opal hue which marks our own deserts seen from far. which is nearly square.