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point: “Now, I think I may conclude that from the point of view of climatology or meteorology, in the present state of these sciences, the hypothesis of Croll seems to be wholly untenable, as well in its principles as in its consequences.”[1]

It seems that the great advantage which Croll's hypothesis promised to geologists, viz: of giving them a natural chronology, predisposed them in favor of its acceptance. But this circumstance, which at first appeared advantageous, seems with the advance of investigation rather to militate against the theory, because it becomes more and more impossible to reconcile the chronology demanded by Croll's hypothesis with the facts of observation.

I trust that after what has been said the theory proposed in the foregoing pages will prove useful in explaining some points in geological climatology which have hitherto proved most difficult to interpret.


PLANETARY PHENOMENA FOR MARCH AND APRIL, 1897.


By Professor Malcolm McNeill.

MARCH.

The Sun "crosses the line" and spring begins just after midnight, March 19–20 P. S. T.

Mercury is a morning star, having passed greatest west elongation on February 15th. At the beginning of the month it rises not quite an hour before sunrise, and may possibly be seen if the weather conditions are very favorable, but its distance from the Sun grows less throughout the month, and it comes to superior conjunction on April 1st.

Venus is an evening star, having passed its greatest east elongation in February. During the month it draws a little nearer the Sun, but sets more than three hours after sunset at the end of the month. On March 21st it comes to its maximum brilliancy, and all through the month it will be visible to the naked eye in full daylight, if the sky is clear and free from haze.

Mars is still a prominent object in the western sky in the evening, and does not set until after midnight. During the


  1. De Marchi, l. c. p. 166.