Note 29 — Chapter I

As a rule, the lines of volcanic disturbance run in a diagonal to the direction of the earth’s rotation—suggesting some tidal action in the gas or fluid underlying the earth’s crust—from N.W. to S.E. along the western side of the great terrestrial areas of Europe, Asia, and America; they may be traced again along the eastern side almost as continuously, trending in transverse lines from S.W. to N.E., as from Mexico to Greenland, and from Sumatra to Behring’s Straits; hence a general parallelism of coast, inland mountain, and axis of volcanic action is inferred.