Periodical Literature. 323 



graphic Society, to the effect that such evidence is deficient or in- 

 conclusive. 



Wolfschiitz of Briinn adduced instances to show that the efficacy 

 of the forest in retaining the waters fails in long continued and 

 extraordinary rainfall periods. According to Honsell, the best 

 wooded basins of the Black Forest, Harz, Spessart, etc., con- 

 tributed most to the floods of the Rhine in 1882. 



Similar experiences were reported from the watersheds of the 

 Elbe in 1897, of the rivers Enns, Traun and Ybbs in 1899, and 

 from the densely forested Riesenwald in Silesia in 1888, 1897 and 

 1903. Yet Wolfschiitz recognizes at least a limited and local in- 

 fluence in certain regions in reducing disastrous floods. 



Lauda, the director of the Austrian Hydrographic Bureau, ad- 

 mits the difficulty of solving the problem and reports very careful 

 and precise observations made in 1903 and 1904 in the basins of 

 two rivers in Moravia, the Bistrizka with 48% forest cover, and 

 the Seniza with only 27%, otherwise the two being geologically 

 and topographically alike, and nearly of the same area. He comes 

 to the interesting conclusion that the preceding weather conditions 

 have a bearing on forest influences. While, generally speak- 

 ing, the retentive capacity of the forest cover is undoubted, it be- 

 comes relatively less in extreme flood times, so that after a certain 

 degree of saturation the run off from the forest is greater than 

 from the unforested area. (Did more rain fall on the forested 

 slopes?) After periods of drouth the retentive capacity of the 

 forest is superior, so that a rainfall after three months' drouth in 

 the better forested basin became noticeable in the river two days 

 later than in the less forested. 



Conclusiveness of these observations is doubtful. 



A correspondence between Lauda and Tessier, published in a 

 later issue of the same journal, which brings further detail and 

 diagrams of conditions and observations in the two river basins. 



Lauda concludes, that, if, as Tessier demands, it is necessary to 

 prove identical distribution of rainfall in two basins to be com- 

 pared, it will never be possible to demonstrate experimentally the 

 forest influence on floods. 



Ponti, an Italian engineer, asserts experiences of increased 

 floods due to deforestation in Sardinia, Sicily and Campobasso, 

 and of the watersheds of the Adda and Matero, and on the other 



