Page:The American Cyclopædia (1879) Volume XI.djvu/677

 MISSISSIPPI RIVER 659 Indians Omoshkos Sagaigon, and by the French traders Lac la Biche. It is a beautiful sheet of water, clear and deep, about 7 m. long and 1 m. to 3 m. wide, in lat. 47 14' K, Ion. 95 2' W., about 1,575 ft. above the sea. Five creeks fall into Lake Itasca, the principal one of which has its origin about 6 m. distant, in a pond formed by water oozing from the bases of the hills known as Hauteurs de Terre, which are about 100 ft. high. The Mississippi at the out- let of the lake is 10 or 12 ft. wide and 18 in. deep, and flows N. E. over petty falls and rapids through a series of small lakes and marshes till it reaches Lac Travers, its most northern point. This is a beautiful sheet of water from 10 to 12 m. long and from 4 to 5 m. wide, surrounded by wooded hills sloping to a beach of pure white sand. From .Lac Travers the river flows S. E. and S., and in the first 25 m. is broken into a series of small rapids, from the foot of which it flows with an even current 40 or 50 yards wide and from 2 to 6 ft. deep to Cass lake, which has an area of about 120 sq. m. ; thence S. through a series of savannas, separated by several lakes, to the falls of Peckagama, where it is compressed into a channel 80 ft. wide. Here the river rushes down a rugged bed of sandstone 20 ft. in 300 yards. Below these falls the river is very crooked, and averages about 40 yards in width. It is broken by six rapids between Swan and Sandy Lake rivers. Savanna river enters the Sandy lake, and is the main canoe route between the Mississippi and Lake Superior. From the outlet of Sandy lake to Pine river, 100 m., the river presents several rapids and islands, and receives a number of small tribu- taries. Crow Wing river, the largest tributary above the falls of St. Anthony, is nearly equal to the Mississippi itself. The Elk river, the Little falls, Big falls. Prairie rapids, and St. Francis river follow in the order named ; and finally the falls of St. Anthony are reached, where the river pitches over a perpendicular face of sandstone 18 ft. high. An island at the brink of the falls divides the current into two channels, the largest of which flows by the west side, and affords a great water power. Including the rapids above and below the falls, the entire descent of the river is about 65 ft. within three quarters of a mile. These falls are about 2,200 m. from the gulf of Mexico, and constitute the natural head of steamboat navi- gation ; but small vessels ply regularly above the falls for several hundred miles, according to the stage of water. The next natural obstruction to navigation below the falls of St. Anthony are the Rock Island rapids, extending from Le- claire to the cities of Rock Island and Daven- port, a distance of 14 m. The descent is 24 ft. at extreme low water. The bed of the river throughout the rapids is stratified limestone, more or less folded, and forming chains or barriers which extend entirely across the chan- nel at six or seven points. In 1866 congress directed the removal of these chains, and also the improvement of the lower or Des Moines rapid, 130 m. below the upper rapid, and be- tween Montrose and Keokuk. The length of the latter is 12 m., and the descent 23 ft. at low water. Before the improvements were under- taken, there was about 11 m. of deep water and good navigation on the upper rapids, and only 3 m. on the lower rapids. The duty of devising plans for the improvement of the rap- ids was assigned to Gen. J. H. Wilson, U. S. A., who recommended that the obstruction at the upper rapids should be removed mainly by the use of coffer dams (see DAM, vol. v., p. 650), and that the lower rapids should be improved by similar means, supplemented by a lateral canal 7 m. long, 300 ft. wide, and having three locks each 80 ft. wide and 350 ft. long. A board of engineers approved these plans, and congress ordered them to be carried into effect. The improvements, under the supervision of Gen. Wilson and his successor Col. Macomb, have been pushed forward as fast as the appropria- tions would permit, and are now (November, 1874) almost completed at the upper rapids, while four fifths of the work has been done at the lower rapids. The improvements will cost about $5,000,000, and when completed will enable the largest boats to pass the rapids, whenever they can reach them either from above or below. But the navigation of the entire Upper Mississippi is rendered very diffi- cult during the dry season by the frequent re- currence of .sand bars; and although the gov- ernment has done something by the use of dredge boats and wing dams to deepen the water on the worst of these, no systematic plan of improvement has yet been devised or can be carried out till a much denser and richer population shall inhabit the regions to be bene- fited. But it is safe to say that between the falls of St. Anthony and the mouth of the Ohio there is water enough at the driest sea- son, if properly regulated and controlled, to give a navigable depth of 6 ft. and ample width for all uses to which it can be put. The Mis- sissippi river, from the mouth of the Missouri to the gulf, is 1,286 m. long ; from the source of the Upper Mississippi, 2,616 m. The dis- tance from the Madison fork source of the Missouri to the gulf is 4,194 m., and from the head of the Ohio river at Cloudersport, Pa., to the gulf, 2,551 m. The numerous branches of the navigable waters connected with the Mississippi penetrate all the states and terri- tories between the Rocky and Alleghany moimtains. The capacity of these branches for navigation has been as yet only partially developed, but a careful compilation shows that they constitute a natural system of wa- ter communication having an aggregate ex- tent of about 15,000 m. The following table, taken from Humphreys and Abbot's " Report upon the Hydraulics of the Mississippi River " (4to, Philadelphia, 1861), shows the area of the basins, downfall of rain, and annual drainage of the Mississippi and its principal tributaries :