SIR ROBERT S. BALL appears to admit the correctness of Mr. Culverwell's argument against Croll's astronomical theory of an Ice Age so far as, that “the direct sun-heat received on any parallel at the time of greatest eccentricity is the same as that now received on the parallel not more than three or four degrees north”; and then proceeds to explain, with perfect truth, that “the actual temperature in a region depends, not merely upon the sun-heat there received, but also upon the transference of heat across the boundaries of that region.”