This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1844 edition. Excerpt: ...the formation of the great body of the drift in western New York and the erratic blocks or bowlders," and he conceives " that the scouring and polishing of the rocks has taken place at a period long anterior to the transportation of these northern bowlders, and that their passage over the surface has had little or no connection with this phenomenon." Very similar views as to the physical condition of the region now covered with drift, appear to be entertained by Prof. Mather. Describing the phenomena throughout an extensive area, and assuming about the same amount of submergence, this geologist has entered into an elaborate and ingenious enquiry respecting the character and direction of the great systematic currents which should prevail under the supposed distribution of land and ocean. Conceiving that the configuration of the continent at the drift period was in the main the same as at present, he shows that the great polar or Labrador current and the Gulf Stream being the results of this configuration and the laws of aqueous motion, connected with the rotation of the earth, and its belts of different temperatures, these currents must have existed then equally as at the present day. The Labrador or polar current possessing necessarily a westward travel, he supposes to have flowed over the northern parts of the United States, bringing ice loaded with detritus. The Gulf Stream, deriving from the rotation of the earth an eastward tendency, he supposes to have been parted by the mountain chain then having the form of a great peninsula or island, and one portion to have flowed up the wide plain or valley of the Mississippi, melting by its warmth the ice of the Labrador stream, and causing its freights of rocky matter to be...