GEOLOGY. 293 



Callao, on the 28th of October, 1746; of the Quay of Lisbon, on November 

 1, 17.J-3; and of Xew Madrid, on the 16th of December, 1811, and many 

 other well-known facts of the same kind on record, illustrate still more 

 fully the modus agendi of these physical changes, and demonstrate the 

 existence of subterranean voids to receive falling areas. From this series 

 of facts, Dr. Winslow ascends to others of greater magnitude, like Seneca 

 Lake, the chain of great North American lakes, the German Ocean, British 

 Channel, and Gulf of Mexico, where identity of strata and fossil forms 

 observable in opposite coasts and headlands clearly show former continuity, 

 which can only have been destroyed by sudden and more or less complete 

 engulfments of immense areas of surface. The existence of intervening 

 islands, as of Cuba and Hayti in the Gulf of Mexico, and of Aru between 

 Australia and New Guinea, is additional evidence of this position, they 

 bearing the same relation to surrounding coasts that the ridges of debris in 

 the pit of Kllauea hold to their former connection with the level of the 

 general surface of Mauna Roa. Carrying these observations still further, 

 St. Paul's in the Indian Ocean, which Dr. Winslow personally explored, is 

 found to be the vestige of a sunken continent, the extinct crater of some 

 ancient Cotopaxi or Popocatapetl shattered and split, and opened to the 

 incursion of the sea, by the great catastrophe which revolutionized the 

 Southern Hemisphere during a former epoch. The Atoll formations, inge- 

 niously divined by Darwin to betoken the earlier existence of mountain- 

 ranges and chains of craters, not only strengthen this conclusion respecting 

 a former continent in the Indian Ocean, as represented in the Maldives, 

 Lacadives, and other islands; but their prodigious development in the 

 Pacific Ocean, with evidences and logical deductions drawn from other 

 geographical and geological data, settles the fact relative to the sub- 

 mergence of a continent in that part of the globe now occupied by the 

 Polynesian Islands. Sudden changes of so stupendous a character would 

 profoundly alter the equipoise of the globe, and produce such movements 

 of the ocean as to overwhelm all lands, and give rise to drift phenomena 

 as extensive as those which can be traced in the last geological ages. 



" These deductions, extended into their astronomical developments, ex- 

 plain the unique relation of the moon to the earth, the longest diameter of 

 the former being held steadfastly to tiie planet, while the sun controls the 

 celestial movements of both ; the various inclinations of the axles of the 

 different planets to the planes of their respective orbits; and even the 

 anomalous conditions of Uranus, whose retrograde rotation may be readily 

 accounted for when the fact is recognized that successive revolutions of 

 surface may have been so numerous or profound as to completely invert 

 the planet from its primitive relation to the sun." Comm. 



ON THE THEORY OF GLACIERS. 



It is only within a comparatively recent period that the attention of the 

 modern scientific world has been especially directed to the very interesting 

 and complicated phenomena of glacier action. Attempts had indeed been 

 made by earlier observers to frame theories by which these phenomena 

 could be explained; but further examination proved that the hypotheses 

 thus proposed were not only insufficient to account for, but were in many 

 cases inconsistent with, the results of observation. The more accurate re- 

 searches of the last few years have, however, been attended with better 



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