X CONTENTS. 



Sectiox hi. — Effects of Forests and of the Destruction of 



Forests on Rivers and Streams, - - - 165 



Cases are cited from America North aad South i^p. 166), I'roui France 

 (p. 167;, from Germanyand from the Cape of Good Hope (p. 172) ; 

 illustrative of the flow of streams and rivers varying with the exist- 

 ence and destruction of forests. A resume is given of a treatise by 

 Herr Wex on the diminution of water in springs and rivers, with 

 augmentation of floods (p. 175) ; with reports on the sarne by the 

 Academy of Science of Vienna (p. 199), and by the Academy of 

 Science of St. Petersburg (p. 203) ; and a resume of observations 

 reported by Dr Ernst Ebermayer (p. 204). 



Section IV. — Immediate Effects of Trees in Arresting the Flow 



and Escape of Rainfall, - - - - 212 



There are cited objections to the views of M. Becquerel in regard to 

 the effects of trees advanced by Marshal Vaillant (p. 212); but 

 with these, observations reported by M. Coute-Grand Champs, and 

 M. d'Arboise de Jubainiville (p. 214), by Mr Marsh and by M. Jules 

 Clave (p. 216), showing that trees have the effect of arresting the 

 flow and escape of the rainfall ; observations by Mr Marschand on 

 the increased hydroscopicity, capillarity, and permeability of soil 

 occasioned by the growth of trees (p. 2 17); and additional 

 illustrations of the same supplied by C6zanne (p. 221), by 

 d'Hericourt, and by Marsh (p. 223). 



Section V. — Secondary Effects of Trees in Arresting t\e Flow 

 and Escape of the Rainfall, and thus Equalising to some 

 extent the Flotv of Rivers, . . _ . 225 



The secondary effects of trees in arresting the flow and escape of the 

 rainfall, and thus equalising to some extent the flow of rivers, are 

 illustrated by reference to the effect of floo>ls in washing away 

 earth, and sometimes covering fertile land with infertile earth, in 

 connection with which are cited statements by Marsh in regard to 

 these effects (p. 226) ; and statements by Surell in regard to the 

 prevention of them by the growth of trees (p. 237) ; statements by 

 Cezanne in regard to natural arrest of torrents by forests (p. 242) ; 

 and by Costa de Bastelica on the effect of trees in increasing the 

 humidity of the soil and consequent drainage of water to subter- 

 ranean reservoirs (p. 244) ; of Marchand on the occasion of storms 

 in the Alps (p. 249) ; with a historical narration of the application 

 of reboisem.ent to arrest and prevent the effects of such storms 

 (p. 251). 



Chapter VI. — On, the correspondence between the distribution of 



the Rainfall and of Forests, - ~ . . 255 



There is stated the course to be followed in this discussion (p. 255). 



