VALLEY. 



lanceolate, acute, entire, fmootli, {hining, fingle-ribbed, two 

 or three inches long and one broad. Panicles or cymes 

 fmall, forked, oppofite to the leaves. Flowers fmall, white. 

 Fruit whitifh. Poiret, after the Fl. Peruv. 



VALLET, in Geography, a town of France, in 

 the department of the Lower Loire; 12 miles E. of 

 Nantes. 



VALLEY, in Natural Hipry and Geology, is a traft of 

 ground bordered by hills or mountains on two oppofite 

 fides, between which it extends in a ftraight or waving line. 

 If the valley be fhort, and the length is not much greater 

 than the breadth, it is called an opening, or pafs, through a 

 mountain or chain of mountains. 



Large valleys have generally a number of fmall valleys 

 joining them, like branches to a main trunk. . In almoll 

 every valley there is either a lake or a river, and the magni- 

 tude of the river bears fome proportion to the valley. The 

 lower end of a valley, where the river empties itfelf into 

 a larger river or lake, or into the fea, is generally much 

 broader than its upper or higher end. Some valleys 

 are nearly clofed in at each end, forming elliptical hol- 

 lows in mountainous diftrifts. Such valleys have once been 

 lakes, but the water having worn itfelf a paflage at the 

 lower end, has reduced the lake to a fmall ftream in the 

 middle, or tlie lakes have been filled up by the debris from 

 the adjoining mountains. 



Sauifiire divides valleys into two orders, which he calls 

 longitudinal valleys and tranjverfal valleys. Grand mountain 

 chains are commonly formed of many ranges of mountains 

 running parallel to the highelt or central range, each range 

 diminifliing in height as its diftance from the central range 

 increafes. It is between thefe parallel ranges that longi- 

 tudinal valleys are fituated. SaufTure cites the valley of the 

 Rhone as a ftriking example of this kind of valley. 



Tranfverfal valleys are thofe openings which communicate 

 between the longitudinal valleys, either at right angles with 

 them, or obhquely. It is obferved by Patrin, that the 

 tranfverfal valleys which cut through the central range of 

 mountains, are fometimes nearly horizontal, at leaft for 

 a fhort diftance ; but thofe which cut the collateral 

 chains have always a more or lefs rapid defcent ; and as 

 they are frequently excavations formed by water-courfes, 

 they fometimes prefent correfponding faliant and retiring 

 fides, like the valleys in fecondary mountains ; but it is evi- 

 dent that this effeft is accidental. 



One of the efTential charafters of longitudinal valleys is, 

 that their direftion is parallel with the line of bearing, or 

 range of the beds of which the mountains are compofed. 

 Tranfverfal valleys cut through the beds in the direftion 

 of their Tine of dip or inchnation. See PlateW. Geology, 

 fg. 2. in which the fide of the mountain fronting a repre- 

 fents the beds of a mountain in their line of bearing ; and a 

 fpeftator placed at the ftation a, may be fuppofed to be 

 placed in a longitudinal valley, in which the edges of each 

 bed in the oppofite mountain would appear to range hori- 

 zontally. The fame appearance would prefent itfelf to 

 the fpeftator placed at B, fg-S- A tranfverfal valley 

 cutting through the beds at right angles to the former, 

 would fliew the true dip or inclination of each bed to a 

 fpeftator placed at b, in the former _/ff. 2. The fide E 

 of the mountain reprefents the direftion of a longitudinal 

 valley, the fide G, the direftion of a tranfverfal valley. 



The Alps prefent many longitudinal valleys. The val- 

 leys in the Pyrenees are tranfverfal. This difference has 

 been fuppofed to arife from the central parts of the Py- 

 renees afcending more precipitoufly above the lower beds ; 

 heuce the waters, falling with great impetuofity, have cut 



1 1 



paffages through the lower beds in direft lines, and taken 

 the (horteft courfe to the plains below. 



In the Alps, the currents, being lefs violent, have fol- 

 lowed the courfe of the longitudinal valleys, which had been 

 traced out by nature in the original formation of thofe 

 mountains. 



Some mountain groups are difpofed in forms nearly cir- 

 cular, fo as to include great trafts of flat country, as is the 

 cafe with Swabia, Hungary, Tranfylvania, &c. Thefe 

 circular bafins or valleys have formed lakes, when the rela- 

 tive level of the ocean was much higher than at prefent ; and 

 on infpefting the beil maps, where the inequalities of the 

 furface are delineated, we may be led to fufpeft that a con- 

 fiderable part of Europe has once been covered by thefe 

 lakes, the prefent mountain chains forming the boundaries. 



The Rhone and the Rhine pafs through feveral fmaller 

 circular valleys in their courfe ; and the river Don, in Aber- 

 deenlhire, has its courfe through valleys of this kind. At 

 the mouth of the Don, the rocks confine it to a narrow 

 channel, and give to it an afpeft which would convey the 

 idea of its flowing through a mountainous and rugged 

 country, where no Ipace was left for forming even a com- 

 modious road along its banks ; but on afcending it for about 

 one mile, the hills recede on each fide fo as to form a fpa- 

 cious vale, through which the river flows in a flow ma- 

 jeftic courfe for many miles. Nor is the profpeft here uni- 

 form, but agreeably diverfified, the hills above Iverury ap- 

 proaching again clofe to the river, through which it feems 

 to have forced its way with difficulty ; then all at once it 

 opens into another fpacious vale, from which the hills recede 

 on either hand to a great diftance ; then it clofes again ; and 

 after another temporary confinement among rocks, hills, and 

 woods, its waters once more open into another plain of 

 great extent. Sucltis the general charafter of this river. 



The Danube, whofe hiftory has been fo well illuftraled bv 

 the count de Marfigli, has its fource in the mountains of 

 Swabia, from whence it paffes through Swabia, Bavaria, 

 Auftria, Hungary, and Walachia, into the Black fea. Swabia 

 is a great circular valley, from which the Danube efcapes 

 by a narrow opening into Bavaria : during its progrefs 

 through Bavaria, it paffes through feveral circular valleys 

 into Lower Auftria, which is alfo a circular valley. It 

 flows through Auftria, and at Prefburg, where the valley is 

 nearly fhut up, it forces its way through rocks and hills into 

 Hungary, which is one of the moft extenfive circular valleys 

 in Europe. At the lower extremity of Hungary, the river 

 is again forced to feek its way through a narrow rocky 

 channel to Orfova, which is the only opening between 

 Hungary and Walachia. It now continues its courfe 

 through Walachia, and at length falls into the Black fea. 

 We have a continuation of this chain of valleys, although 

 ftill filled with water, in the Black fea, the fea of Marmora, 

 and the Mediterranean. 



The valley of Cafhmere prefents one of the moft ftriking 

 examples of a circular bafin or valley, containing a fmall 

 lake, which has probably once filled a confiderable part of 

 the great cavity formed by the furrounding mountains. 

 " This happy valley," fays Mr. Pennant, " this Hindoftan 

 paradife of the Indian poets, is of an oval form, about 

 eighty miles long, and forty broad, and is fuppofed to have 

 been once entirely filled with water, which having burft its 

 mound, left the vale nourifhed to the moft diftant ages by 

 the fertilizing mud of the river, which fed its expanfe. 

 This delicious fpot is furrounded by mountains of vail 

 height and rude afpeft, covered with fnow, and enchafed in 

 glaciers, in which this enchanting jewel is firmly fet." 



The formation of valleys has been by fome philofophers 



alcribed 



