REPORT OF THE SPECIAL COMMITTEE FOR THE CONSIDERA- 

 TION OF THE MEMOIR OF MR. HOFRATHES G. WEX, UPON 

 THE DIMINUTION OF THE WATER OF RIVERS AND STREAMS. 



[Presented Ai>ril 23, 1874, to the Royal Academy of Vieuua. — Translated from the Ger- 

 man by M. A. Henry.] 



The special committee of the Imperial Academy, called at the request 

 of Mr. Hofrathes Wex, and which that geutlemau was iuvited to attend, 

 was composed of the following regular members: Feuzl, Jelinek, voa 

 Schrotter, Stefan, and Suess; and held three sessions, on the 13th of 

 October, on the 18th of December, 1873, and the 18th of January, 1874, 

 during which the facts contained in the memoir of Mr. Wex, and the 

 recommendations based thereon, were thoroughly discussed. 



As basis for the final conclusion attained by the commission, it seems 

 advisable to give a short resume of the observations and deductions 

 contained in the paper of Mr. Wex. 



The author first gives various data, from the second volume of 

 Berghaus's statistics, in regard to the height of water, of the Rhine at 

 Emmerich, of the Elbe at Magdeburg, and of the Oder at Kiistrin ; 

 according to which the mean and lowest heights have sunk considerably 

 in the course of time, while the high water is exhibited more frequently 

 and in greater elevation. 



Dr. Berghaus was led, through the examination of the heights of the 

 water of the Elbe and the Oder, to the conclusion that in both these 

 streams the quantity of water, when at its lowest level, had considerably 

 decreased, and expressed the opinion that these rivers threatened to 

 disappear from the ranks of navigable streams if this diminution con- 

 tinued in as great proportion as at that time, 1781. 



Mr. Hofrathes Wex arrived, through long years of observations, at 

 the same result as Berghaus, and declared that there is a continued 

 decrease in the water of the above-named rivers, and also in those of the 

 Vistula and the Danube. His assertion excited objections on all sides. 



In opposition to it — 1. The imperial Prussian private government 

 surveyor, F. Hageu, through measurements of the high and mean 

 heights of the Rhine at Dusseldorf, found, it is true, a slight diminution, 

 (on an average 2.9 and l.G lines a day,) he explained this, however, by 

 the recent alterations made in the stream, which promoted the removal 

 of the ice, and the escape of the high water. 2. The imperial hydrau- 

 lic inspector, Maass, found from the record of 143 years of the observa- 

 tions of the heights of the water of the Elbe, at Madgeburg, a consid- 



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