Page:The New International Encyclopædia 1st ed. v. 17.djvu/191

KIVER. 171 RIVER BRETHREN. uniform level long enough, or if it is slowly rising, a delta will actually be built. But where the movement of the laud is downward, or has recently been one of subsidence, deltas cannot be ex[iected. Tliis explains the absence of deltas in Xiirlheastern America and Xorthwestern Kurojje, and accounts for the many bays, estuaries, and fiords; for in these sections the lowering of the land has drowned the seaward ends of the val- leys and transformed them into arms of the sea. Tlius the lower Hudson below Troy is for 150 miles an estuary and not a true river. The true Hudson is the portion from the Adirondacks to Troy, and that below may be called a tidal river. By the mineral load which rivers carry, im- portant work is being performed. A large variety of alkalies and salts is held in solution and much of it is carried to the sea. It is the carbonate of lime obtained by the action of the water on the land that supplies the materials used by sea animals in the construction of their shells. This river load is therefore important in making possible the coral reefs of the present and the beds of limestone formed in ancient geological _ time. Since the river water carries small iiuanti- ties of salt to the sea, and since it must be left behind when vapor rises into the air from the water surface, it seems probable that the salt- iiess of the sea is due to this action of rivers. The mechanical burden of the stream is partly suspended in the river water, though immense quantities are pushed along the bottom in the form of fine silt, sand, gravel, and stones, ac- cording to the velocity of the water. Some of this is temporarily lodged in the quieter por- tions of the stream, and, as we have seen, on the flood plains and deltas ; but since it is journeying toward the sea, much of it eventually reaches that goal, and there it is accumulated, often after being worked over and distributed by waves, tides, anil currents. It is from this source that the sedimentary rocks which form so large a por- tion of the continents were once derived by the wearing down of ancient lands, the transporta- tion of ancient rivers, and deposition in the early seas. From these facts it is evident that the work of rivers nuist be of great importance in the change of the form of the land. They are operating now and have been working through such long periods of past time that their results have been tremendous. It is estimated that 8,370,000 tons of mineral matter in solution are every year re- moved by nmning water from the surface of England and Wales. At this rate the surface of the country would be lowered one foot in 12,078 years as a result of solution alone. The Missis- sippi River carries in suspension or by dragging sediment to the amount of TTTilTT °f "^^ total weight of the water. The river annually carries into the sea a quantity of mud which would make a prism 208 feet in height with a base of one square mile. About liiO.OOO.OOO tons of dis- solved mineral matter is also annuall.v carried into the sea through the INIississlppi. See Erosion. In the course of this vast denudation rivers are subjected to many changes, some of them of an accidental kind, such as those described above as due to glaciation, etc., others due to their nor- mal development. Among the latter changes the most important is that group which results from Vol. XVII.— 12. the changes of divides. There is a battle in prog- ress between the headwaters of opposing streams. The one that has the most rajiid slope to the sea, or the greatest rainfall, cu- the softest rock to excavate, has an advantage over a less favorably situated opponent. It will push the divide back in consciiuence. Most often this is nc.'onq)lished by a very slow backward eating, but occasimially a successful stream ta|)s a large headwater o"f an opposing system and bodily lends it into its own drainage system. Such" rivers havi> Ix-en called river pirates. It has apparently been by such headwater changes that the rivers which now cross the Appalachians through watergaps, like the Delaware, Susquehainia, and I'otomac, have eaten tludr way back to the westward side of this mountain system, Bim.ioGRApuY. For the statistics of river sys- tems, consult Murray, "On the total Anmial Ua'in- fall on the Land of the (;iobe, and on the Udation of Rainfall to the . nual Disdiarge of Kivers," in Sooltish (jeof/raphictil .1/«;/«-ih,' (Edinburgh. 1887) ; for matters pertaining to irrigation, es- pecially in the Tnited States, consult the Krport of the Commission of Irrigation. U. S. Connrt'.is, 1800, and the Anniuil liiports of the Ht/drng- rnpher, V. .S. Geotogicat Siirrri/ (Washington); on the question of riparian rights. Ilii.'giris. Trrn- fise on the Laic Relating to the I'otlution and Obstruetiou of Watercourses (London. 1877); for special information with reference to the Mis- sippi River, Morrill, "The FIimhIs of the Missis- sippi River," in Weather Bureau Reports of the Mississippi River Commission (Saint Ixiuis) ; for a general physiographic or geological history of rivers, Greenwood, Rain and. Rivers ( London. 1876); Russell, Rivers of Sorth America (New York, 1808); id.. River Derclnpment (London, 1808) ; Davis, "Seine, Meusc, and Moselle." in National Geographic Magazine, vol. vii. (Wash- ington, 1806). Consult also various articles in the Report of the International Inland Xaviga- tion Congress (The Hague. 180.5) ; the Report of the International Congress on Irrigation (Paris, 1000) ; and the authorities referred to under the articles on the various rivers. See GEOLOGY; Geogr.^piiy ; riiYSioGR.^niY. etc. RIVER BRETHREN, The. The name ap- plied to a group of Christian bodies supposed to be of Mennonite origin. They originated in a colony of Swiss who settled near the Susquehanna River in eastern Pennsylvania in H.'iO. During the revival of 1770 congregations were formed among the converts, with .lacob Engle as their first pastor. In many points of their faith and practice the River Brethren resemble the Men- nonites and in part also the Dunkards. They baptize by trine immersion ; observe foot-washing as a religious rite; use the kiss of greeting be- tween persons of the same sex; teach non-resist- ance and nonconformity to the world ; inculcate plainness in dress and living; abstain from polit- ical activity, although they do not neglect the regular duties of good citizens; are strict in the observance of the Sal)bath ; and endeavor to order their lives according to the precepts of the Bible. Three branches of the River Brethren arc recognized: (1) The Brethren in Christ, the largest and having the most complete organiza- tion, with district conferences and a General Con- ference which meets annually. They are most numerous in Pennsylvania. Kansas, and Ohio,