METEOROLOGY OF THE MOUNTAINS AND PLAINS OF N. A. 629 



the continent. This may, therefore, be not inaptly called the " Water Dome of 

 North America ! " 



Stretching eastwardly from this **Dome" to the mouth of the St. Lawrence 

 River on the Atlantic Coast, lies a declining ridge, from which waters run north 

 into Hudson's Bay, and south by the Mississippi, Illinois and Ohio Rivers and 

 their tributaries, into the Gulf of Mexico, and east of the Alleghenies by the 

 Potomac, Delaware, Hudson, Connecticut and other rivers into the Atlantic 

 Ocean. 



Besides all these mighty rivers that have their geneses in the direct pathway 

 of these west winds across the continent, and cradled upon the crest of the ridge 

 just described, lie the great Lakes of Superior, Michigan, Huron, Erie and On- 

 tario, which alone are estimated lo contain one-half of all the fresh water resting 

 upon the face of the earth, and which, notwithstanding the necessarily enormous 

 drain from them by evaporation, yet have always such a surplus of water as to 

 keep in unvarying flow from them the majestic St. Lawrence River. 



Now the waters which supply the rivers radiating from what I have termed 

 the "Water Dome," all come from this west wind from the Pacific, as I believe 

 do also those which supply the other rivers in the Mississippi basin west of the 

 Allegheny Mountains, together with those that fall into and make the great lakes. 

 Whether or not the waters that go into the rivers east of the Alleghenies come 

 from the same source is doubtful. I think, however, that through local agencies, 

 they come from the gulf stream of the Atlantic, Yet it is not unreasonable to 

 believe" and affirm that by reason of the waters that do come from the prevailing 

 west winds from the Pacific that \\. \s \.\\q Kuro-Siwo of the Pacific that irrigates 

 and fructifies the heart of the continent of North America. 



Now it may be asked, what has all this to do with the aridity of the alkaline 

 plains of Colorado and New Mexico ? Very much, as I shall endeavor to show, 

 by first calling your attention again to the water supply that is carried under the 

 wings of this west wind from the Pacific Ocean and distributed nearly, if not 

 quite, across the continent (when not interrupted by the condensing power of 

 intervening mountain ranges,) since that is the gauge by which the quantity of 

 water carried by these winds can be measured ; and if found in one portion of 

 these winds, it is not unreasonable to believe that other portions of these same 

 winds carry a corresponding quantity. But let us now see what becomes of that 

 supply from that portion of these winds which strikes the land south of Oregon, 

 and which, being slightly chilled by the coast range of mountains and hills, give 

 out moisture enough to envelope the coast with fogs and clouds during many 

 months of the year. Passing thence into the interior, these winds are thrown 

 upward against the cold flanks and peaks of the Sierra Nevada, where being con- 

 densed, they crown the latter with their coronets of eternal snow. Descending 

 the eastern slope of the Sierra Nevada Range, these winds reach the plateau of 

 Utah and Arizona before described, so robbed of moisture that the earth's steril- 

 ity is but the evidence of its unslaked thirst. 



Continuing eastwardly, these west winds then climb the western slopes of the 



