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shifted by the winds and their height does not exceed 1,80 

 mts. above low river. 



The stones or rocks, found in the river Uruguay may 

 be divided into two classes : 



1 st those wich originally formed part of the superior layer 

 of the ground and through its socavation when the river 

 bed was formed sunk down to the place which they actually 

 occupy; 2 n(1 those which belong to the inferior layers and 

 form compact banks. 



The first are sandy and have more or less the hardness 

 of grindstones, for the reasons given before they are loose 

 stone and form heaps that can be extracted very easily. 



The second are equally sandstone and those of the Co- 

 rralito» bar seem to have been formed by a conglomerate 

 of limestone the softest parts of which has been destroyed, 

 the harder remaining and these once being silicified, 

 besides getting firmer, have adopted irregular shapes. For 

 this reason they are so dangerous to the hulls of the vessels. 



There are also heaps of stones below the port of Pay- 

 sandu and at the mouth of the Arroyo Sacra on the Orien- 

 tal coast, and on the Argentina coast below the Arroyo 

 Urquiza. Those stone heaps form the breakers of Pay- 

 sandu, of the «San Francisco bar, of the limekiln Co- 

 lombo, of Pepeaji, and of the arroyo Spina or «del Griego». 



The sandstone in beds has been found by borings at 

 Ohapicuy and in the Port of Concordia. 



The stones of the Hervidero and Salto Chico are in some 

 parts loose and in others they form beds; their texture 

 shows rather a plutonic than a sedimentary origin. They 

 are very hard in comparison with those named before. 



Rocks. 



ACTUAL NAVIGATION 



The actual navigation of the River Uruguay consists of : 

 the ocean navigation which goes to below the San Fran- 

 cisco bar and the coastwise navigation wich reaches to 

 Concordia (Salto more correct). 



The ocean navigation is actually clone by vessels from ocean navigation. 



