Increased range of the tides means increased circulation in the waters of the oceans, especially an increased interchange between the warm North Atlantic and the cold Arctic waters. It also means than an unusual amount of ice is brought down from high into low latitudes. Wide local variations of temperature of the surface waters of the oceans cause increased cyclonic activity, and hence we may expect a generally increased storminess at times of maximum “tide-generating force,” and the reverse at times of minimum. For the last maximum (A.D. 1434) Pettersson is able to adduce a good deal of historical evidence of increased storminess in north-west Europe and bad ice-conditions near Iceland and Greenland, while Huntington has found an increase of rainfall shown by the big trees of California. The next preceding maximum, that of 360 B.C., marks the culminating point of the Peat-bog phase. The Norse sagas and the Germanic myths point to a severe climate about 650 B.C., which destroyed an early civilization. This was the “Twilight of the Gods,” when frost and snow ruled the world for generations. The period was the Early Iron Age, when civilization deteriorated greatly in north-west Europe. Of the maximum of 2100 B.C. there is no trace. It is possible that the great Atlantic submergence of the Maritime phase is connected with the tidal maximum of 3500 B.C., but the phenomena were on a scale so much greater than those of the more recent maxima that this can hardly have been the sole cause. The minima should have been characterized by periods of relatively quiet stable climate with little ice near Iceland and Greenland. That the last minimum, in A.D. 530, was such a period there is considerable evidence in the high level reached by civilization at that period in Scandinavia and by the revival in Ireland. Again, about 1200 B.C., in the early part of the Peat-bog phase, there is evidence of considerable traffic by sea between Scandinavia and Ireland. The Irish Museum has lately discovered a hoard of gold objects dated about 1000 B.C., in which the designs show a Scandinavian origin. The minimum of 2800 B.C., which occurred in the Forest phase, may have contributed to the dry climate of that period, but otherwise has left no trace. Although at first sight the effect which Pettersson sets out to explain seems out of all proportion to the smallness of his cause, the coincidences after 2000 B.C. are extremely interesting, and suggest that after the land and sea distribution reached its present form the astronomical cause adduced by Pettersson was possibly effective, but before that date the astronomical cause, if it existed, was masked by the much greater climatic variations due to changes in the land and sea distribution.