RIVER. 



How violently in rainy feafons, and are dry in dimmer, 

 are probably owing to rains ; but there are fome fprings 

 which difcharge more water annually than all that falls 

 in rains and dews in the neighbouring country. The 

 great perennial fpring, at Willowbrig, in Stallordfhire, is 

 of this kind, and that of the Sorgue, in France, is much 

 more eminently fo ; the river of that name being, accord- 

 ing to GafTendus, navigable up to the very fprings which 

 are its fource. 



But if fuch fprings as thefe difcharge too great a quantity 

 of water for the fupply of rains and dews, how is it poifible, 

 that fuch fmall fupphes ol water as thefe can afford the con- 

 ftant currents of the larger rivers ? The Volga alone, ac- 

 cording to Ricciolus, pours forth as much water in a year's 

 time into the Cafpian lea, as would fuftice to drown the fur- 

 face of the whole earth. The river of St. Laurence, in 

 America, pours forth nearly as much as this. If either of 

 thefe rivers alone do, as has been affirmed, from calculations, 

 difcharge annually as much water as falls in the fame time in 

 rains and mills upon the furface of the whole earth; from 

 whence are all the relt to be fupplied, according to the fvftem 

 of their all being made by rains ; and, particularly, where 

 is left the fupply for the Rio de la Plata, which Ricciolus 

 affirms to be larger than the Nile, the Ganges, and the Eu- 

 phrates, put together ? its mouth being ninety miles wide, 

 and running with that violence into the fea, that it makes it 

 frefh for two hundred miles together. Thefe, and the other 

 rivers of the fcveral parts of the globe, upon a very moderate 

 calculation, difcharge at leaf! five hundred times as much 

 water into the fea, as falls upon the whole furface of the 

 earth, in rains, mills, dews, fnows, &c. in a like fpace of 

 time. 



As it is evident, therefore, that thefe cannot be fupplied 

 by rains, fo neither is it poffible that the feveral hot fprings 

 and the fait fprings can be fupplied that way : the origin of 

 fprings alfo in places where there falls little or no rain, and 

 where the confervatories mufl needs be too fmall to contain a 

 fupply, are great proofs that rain and mifls are not the 

 origin of fprings, at leait not in all places. The ifles of 

 Mago, Rotunda, and the Strophadcs, and the rock on which 

 the Maiden Tower Hands in the Thracian Bofphorus, cannot 

 be fupplied with, or retain a fufficiency of rain-water to 

 fupply conflant fprings, yet fuch are always found running 

 there. 



It cannot be otherwife but that there arc fllbterranean 

 communications between the lea and the fources of fountains, 

 rivers, and the larger fprings, by which thefe are fupplied ; 

 and there arc certainly charybdes which (wallow the lea for 

 thefe purpoics ; and when thefe happen to be Hopped, the 

 largelt rivert have been dried up, and wholly ceafed to run 

 for a confiderable time : this we have accounts in hrftory 

 has happened to the Thames, the Trent, and Medway, in 

 England ; the Elve, the Motala, and Gulfpang, in Sweden, 

 and other rivers in other countries. If, on the other hand, 

 thefe charybdes happen to be loo open, frefh-water fprings 

 depending upon them will become fait. This we have in- 

 stance of in hiitory alfo ; and even fo old a writer as Pliny 

 has faid that this once happened in Caria near Neptune's 

 Temple. (Plot, de Origine Foutium.) See EVAPORATION 



and Spring. 



R.IVERS, Phenomena and Variations of. Rivers are found 

 fubjeet to great alteration!, at different feafons of the year, 

 day, &c. (rem frequent rains and melted fnow. Thus in 

 Peru and Chili many of the rivers are almoll infenlible in the 

 night-time, and only flow by day, as being then augmented 

 by the dillolution of the fnow on the mountains Andes. 

 Thus the Volga aboundu in water in May and June, fo as 



to cover the fand-banks, &c. which all the reft of the year lie 

 bare, fo as fcarcely to allow a paflage to the loaded mips. 

 Thus alfo the Nile, Ganges, Indus, &c. are frequently fo 

 increafed, as to overflow ; and that either in the winter 

 from rain, or m the lummer, from the melting of the fnow. 

 Some rivers bury themfelves under ground in the middle of 

 their courfe, and break out again in other places, like new 

 rivers. Thus the Niger, which fome cofmographers erro- 

 neoully derive by a fubterraneous channel from the Nile 

 becaule it fvvells at the fame time with the Nile, without 

 any other apparent caufe— the Niger itfelf has been fup- 

 poted by fome to be hidden under the mountains of Nubia, 

 and to rife again on the weifern fide of thofe mountains ; 

 whereas, in reality, it is loll in lakes or fands. Thus, alfo, 

 the I igns is loll in the mountain Taurus, &c. 



Ariltotle, and the poets, mention feveral fuch rivers about 

 Arcadia : Alphe-.:s, a river of Arcadia, is particularly 

 tamed. This, being fwallowed up in the ground, is fuppofed, 

 by the Greek authors, to continue its progrefs under the 

 earth, and under the bottom of the fea, into Sicily ; where, 

 breaking up near Syracuie, it forms the river Arethufa. 

 The great reafon of this opinion was, that, every fifth 

 lummer, the river Arethufa, in Sieilv, call up the dun? of 

 cattle about the time of the celebration of the Olympic 

 games in Achaia, when the dung of viftims was ufed to be 

 can into theAlpheus. 



Some rivers empty themfelves into the fea by one mouth, 

 fome by feveral. Thus, the Danube opens into the Euxine 

 fea by leven mouths ; the Nile by feven ; and the Volga by at 

 lead feventy. The caule of this variety of months Varenius 

 attributes principally to the banks of fand, &c. accumulated 

 in them ; which, gradually increaling, form iflands, by which 

 the channel is divided into feveral branches. Indeed, the 

 ancients tell us, that the Nile formerly only emptied itfelf at 

 one mouth, called the oftium Canophum ; and add, that the 

 other fix are adventitious, or artificial. 



The channels of rivers, except fuch as were formed at the 

 creation, Varenius endeavours to prove to be all artificial, 

 and dug by men. His rcafons are, that, when a new fpring 

 breaks forth, the water does not make itfelf a channel, but 

 fpreads over the adjacent land ; fo that the people have been 

 necefhtatrd to cut it a channel, to fecure their grounds ; and 

 that a great number of channels of rivers are certainly known, 

 from hiflory, to have been dug by men, &c. 



As to the queflion, whether thole rivers which run into 



others, have made themfelves that way by their own 



on, or have been turned thither in canals cut by men? 



kes the latter to be the more probable ; and conclude* 



lame of the arms, or 1. ranches, of rivers, and of the 



turns by which iflands are formed in the Taiuis, Volga, 



<xc. 



To the queflion, why we have no fait rivers, when there 



are fo many ialt fprings ■ he anfwers, that it is becaufe men, 



. no occafion for Ialt water, have not dug channels to 



conduct the water of Ialt fprings ; fait being procurable at 



lefs expence. 



The water of moil rivers carries with it particles of metals, 

 minerals, lands, or oily and fat bodies, fcc. Thus, fome 

 rivers bring fands intermixed with gTai gold; of 



which kind is, I. A river m Japan. 2. Another in the 

 illand ol Lequeo, near Javon. 5. A rivulet m Africa, 

 called Arroe, breaking out ol the foundation of the moun- 

 tains ol the moon, in w Inch there are golden mines. 4. A 

 river in Guinea, where the negroes ieparate the gold-dull 

 from the land, and fell it to the Europeans, who traffic thither 

 for that very purpole. 5. In feme rivulets near the city 

 of Mexico, there arc grains of gold taken up, cfpccially 



after 



