===========+======================+=============+================= | DAYS AFTER WINTER | | MUNDANE | SOLSTICE OF SOUTHERN | MARTIAN | ASPECT DATE | HEMISPHERE | DATE | -----------+----------------------+-------------+----------------- January 25 | 12 | December 27 | Blue-green March 6 | 52 | January 16 | Blue-green April 4 | 81 | January 31 | Chocolate April 12 | 89 | February 4 | Chocolate April 30 | 107 | February 13 | Faint chocolate May 8 | 115 | February 17 | Faint chocolate May 12 | 119 | February 19 | Faint blue-green June 11 | 149 | March 6 | Faint blue-green June 15 | 153 | March 8 | Faint blue-green July 16 | 184 | March 23 | Pale bluish green ===========+======================+=============+================== Here, as in 1903, a chromatic rise and fall is evident; the culmination of the change occurring in Martian early February about ninety days after the winter solstice. That it was not of long duration is also indicated. If we examine the evidence for the two portions of the _mare_ separately, the northern and the southern, as in 1903, we find it as follows:— =========+==========+=========+==========+==========+=======+======== | | | | | | MARTIAN | DECEMBER | JANUARY | FEBRUARY | FEBRUARY | MARCH | MARCH DATE, | (27) | (16) | (2) | (16) | (7) | (23) ---------+----------+---------+----------+----------+-------+-------- | % | % | % | % | % | % Northern | 50 | 50 | 0 | 10 | 25 | 30 Southern | 50 | 50 | 20 | 20 | 25 | 30 ===================================================================== Here again a slight retardation in the advent of the metamorphosis is observable in the southern portion. There would seem to be a difference in the time of the change between the two years of fifteen days, 1905 being by that much the later. But with points of reference themselves thirty days apart, it is possible the two more nearly coincided than here appears. Unlike the ochre of the light regions generally, which suggest desert pure and simple, the chocolate-brown precisely mimicked the complexion of fallow ground. When we consider the vegetal-like blue-green that it replaced, and remember further the time of year at which it occurred upon both these Martian years, we can hardly resist the conclusion that it was something very like fallow field that was there uncovered to our view. [Illustration: Mare Erythræum Martian date. February 21]