I have just read Mr. Hill's criticism on my views as to the cause of the Glacial Epoch, and have to thank him for the fair and courteous way in which he has treated the subject. I fear Mr. Hill has come to his conclusions somewhat too hastily. He appears to me to have totally misapprehended the real effect of fogs and a snow-covered surface on climate, and also the influence of eccentricity on the trade-winds. But I must defer for the present entering into any discussion on the matter. My object just now is simply to direct attention to an erroneous assumption which appears to lie at the base of nearly all the objections which have been urged against the theory that the Glacial Epoch resulted from an increase of eccentricity.