72 Dr Forry on the Climate of the United States. 



elude any thing beyond the most general outlines. It was 

 well remarked by Malte-Brun, that " the best observations 

 uj)on climate often lose half their value, from the want of an 

 exact description of the surface of the country." Presuming 

 that our readers are sufficiently well acquainted,'/or the pre- 

 sent purpose, with the physical features of the vast region 

 stretching from the Atlantic to the Pacific, and from the 

 Gulf of Mexico to the inland seas on our northern frontiers, 

 the descriptions will be limited to such parts alone as are 

 essential. 



One of the most striking characteristics of the physical 

 geogTaphy of the United States, and which, it will be seen, 

 induces the most remai'kable modifications of climate, is the 

 existence of those great inland basins of water which lie on 

 our northern frontier. Of so vast an extent are these ocean- 

 lakes, that one of them (Lake Superior) has a circuit, follow- 

 ing the sinuosities of the coast, of 1750 miles. The basin 

 of the St LaA^i'ence is truly a region of " broad rivers and 

 streams," containing, it is estimated, an area of 400,000 

 square miles, of wliich 94,000 are covered with water. From 

 the western extremity of Lake Superior to the Gulf of St 

 Lawrence, the distance is about 1900 miles. These ocean- 

 lakes have been estimated to contain 11,300 cubic miles of 

 water, — a quantity supposed to exceed more than half of all 

 the fresh water on the face of the globe. The deepest 

 chasms on the sui'face of either continent are presented per- 

 haps by the depression of these lakes ; for though elevated 

 near 600 feet above, the bottom of some is as far beneath, 

 the level of the ocean. Lakes Huron and Michigan, which 

 have the deepest chasms, have been sounded to the amazing 

 depth of 1800 feet without discovering bottom. 



The following table, which gives the mean length, breadth, 

 depth, ai'ea, and elevation of these several collections of water, 

 is taken fi'om a recent report made by Douglas Houghton, 

 Esq., state geologist of Michigan. 



