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lent French word, brouille— perhaps most properly rendered into English 

 by blear; as, for instance, minisoiah, blear water, or the entrance of the 

 blear water. I have entered upon this explanation, becanse the word 

 sotah really means neither clear nor turbid, as some authors have asserted; 

 its true meaning being readily found in the Sioux expression is/da sotah, 

 blear eyed. After the same manner, they call the Falls of St. Anthony rara 

 — from irara, to laugh— descriptive of the imitative sound they are sup- 

 posed to produce. The Chippeways are more accurate; by them, the falls 

 are called Kakabiknh., or severed rock ; and the St. Peter's river, Ashkibogi- 

 Sibil the Green Leaf river. 



From actual measurements made by Mr. H. Sibley and myself, the width 

 of the St. Peter's at the crossing-place, above its confluence, is 320 feet; 

 that of the Mississippi, below Fort Snelling, and outside of the gorge 

 whence it issues, is 576 feet. The intervening space between these two 

 measured spots is the rocky point on which the fort stands, and a grassy 

 bottom, the whole measuring 1,263 feet. The mean height of the plain 

 supporting Fort Snelling and the Indian agency is 106 feet above the com- 

 mon low water of the two rivers 3 and the height of the Pilot Knob above 

 the same level, 262 feet. 



Of the numerous springs that issue from the foot of the adjoining 

 bluflfs, there is one particularly deserving of notice. It is very abundant, 

 and perfectly shaded. It goes by the name of Baker's spring. Having 

 taken its temperature three times a day during twenty days of the month 

 of July, 1836, and then again during the following winter months, I never 

 found it to vary more than 46*^ in July, and 45° 5' in January. Either 

 cipher may then be taken as the mean annual temperature of the climate 

 of St. Peter's; and this result accords with the thermometrical observations 

 made during several years at Fort Snelhng, which gives the mean at 45° 

 37'.* 



The geolo^jical account of this district is plainly expressed : it embraces 

 the rocks forming the upper strata of the formation which characterizes 

 the Mississippi bluffs from the Prairie du Chien to this place ; the whole 

 series of which to the west, in the most prominent localities, has been de- 

 scribed by Professors Troost, Hildreth, Locke, Owen, Mather, and James 

 E. Hall, in their several reports, officially printed, or otherwise furnished 

 to the scientific records of the day. 



The geological features of the country, in the ascent of the Mississippi, 

 from the St. Peter's to the Falls of St. Anthony, are as follows: 



1. Fine grained, unstratified sandstone, constituting the base of the 

 bluff, and ranging in thickness between 60 and 80 feet, of a very friable 

 character; each grain being a crystalline fragment of quartz. In some 

 parts of the mass, the grains are stained with oxide of iron ; while in others, 

 they are perfectly white. It is probable that the sand furnished by the 

 latter would serve in the manufacture of glass. 



2. A compact sublamellar limestone of variable colors, as fawn, yellow- 

 ish-buff", or grayish. It contains many fossils, but very irregularly dis- 

 tributed in the mass; some being covered with brilliant crystals of car- 

 bonate of lime, and others entirely mineralized. This bed is from 8 to 

 12 fdet thick, weathering into layers of from two inches to a fo^t thick. 

 The limestone under consideration resembles much, in mineralogical 



* Army Meteorological Regi.sier, p. 95. Philadelphia, 1840. 



