j§§i -Sudden iKFLEX of 



Mafcatet in the fmaUpoints, u)Jicate (he (and banks where the Mafcaret always 

 "*'^* commences; tl^t* parts occupied by fmall lines, are .the places 



where fhe waves occupy the whole breadth of the river. The 

 dotted parts* indicate the re-entring angles, wliere the fand 

 banks are found which are depofited by the counter-current. 

 It is here principally that the Mafcaret rolls with all its fury 

 over' tliG mud of the river. On the banks the falient angles^ 

 are the places where the Mafcaret quits the fliore, occupies 

 the" whole river, and runs> upwards, accompanied by many 

 confiilerable waves, which facceed each other, till another 

 re-entring angle occurs, whtire it again refumes its firft form. 

 It is thus that ihefe who dwell in the vicinity of Bourdeaux 

 wilnefs without emotion twice each day, when the waters arc 

 low, fo extraordinary a phenomenon, without any one thinking 

 of examining into the caufe of it, or evefl of communicating 

 the particulars to naturalifts. 

 The tide is the The pfimary caufe of this riling of the water is the fame as 

 primary caufe (hg^ of the tide in all rivcTs; and if the Mafcaret occurs on vety 

 ' few rivers, it i-s bfecaufe their beds are not formed in a manner 

 necelTary to proddCe it, and have not the fame difpofition as the 

 Gifondeand Dordogne: they have either too little or too great' 

 a cufrent; their vi^aters are not fufficiently low, or when they 

 are, the tld^'does not continue long enough ; finally the re- 

 enlring and falient angles are not fuch as they ought to be. M. 

 Sorbie thinks he could tell before hand whether any river would 

 be liable to fi^ch effefliJ, from the form of its plan and the difpofi- 

 tion of its bottom ; and is of opinion that the caufe why more 

 rivers are not fubjecl to the Mafcaret, depends entirely on the 

 Ihape of their beds, and not on any particularity in their tides. 

 The phyfical caufe of that on the Dordogne appears very fimple, 

 M. de la Condamine fays, that on the Amazons it is always at 

 Th.r courfe of the Tiarrovv parts where it is obferved. The caufe is not the fame 

 the Dordogne on the Dordogne, for there is no narrow parts in almo/l its 



dikrib'd, ro , , r •. • • i i • . ^ r 



3 count for the ^^"O'e courle : It IS nearly every where very rapid, and of 

 Mifi-rct, fmall depth, as all thofe rivers are wh'ch have much current. 



It forms, as may be feen in the plan, many turns and windings; 

 and has few ifles : but at each angle a bank of fand is depo- 

 fUed : It defcends, notwithflanding tliefe windings, almoft 

 fiom the eaft to the north- weft. As far as Bee d'Ambes, where 

 it unites with thfe Garonne which is much more powerful than 

 it, and they form together that beautiful arm of the fea, called 



the 



