194 EFFECTS OF FORESTS ON SPRINGS AND RIVERS. 



tions now furnish smaller water supplies to the feeding of the river 

 course than was the case at an earlier period. 



" Dr H. Berghaus has in his work on ' Hydrography' which has 

 been cited, advanced on this point (p. 30) the following doctrines : 



" In some parts of the world it has been remarked, the springs 

 have suffered a loss in the quantity of their water supplies. Thus it 

 is in France in what was formerly Poitou, and in the department of 

 the lower Charente, where there has been remarked a decided reduc- 

 tion of the springs since 1825. 



" The phenomenon is attributable to the desiccation of the land, 

 the cutting of canals, trenches, &c , while Fleuriau of Bellevue has 

 alleged that the cause is to be found in a diminished rainfall. 



" It can also be established by manifold evidence that of late years 

 many springs have dried up, and that in a great many others the 

 quantity of water yielded by them has been greatly reduced ; further 

 it is generally known that several solidly and skilfully constructed 

 aqueducts which erst while conveyed a rich supply of water have 

 become completely useless in consequence of a permanent deficiency 

 of water which has arisen, and that very many old wells known 

 amongst us as inexhaustible have become, since 1852, in consequence 

 of the lowering of the water level in the subterranean strata by 

 which they were fed, in some cases absolutely dry ; and in other 

 cases so impoverished in water supplies that the wells must be annk 

 some fathoms deeper if they would be made permanent sources to 

 meet the demand. 



" From amongst the numerous cases which have become known to 

 me, I shall adduce but a few specimens : 



" It is generally known that the city of Eome, in its pristine glory, 

 with its public fountains and baths, and its several aqueducts, was 

 exceedingly richly provided with water ; some of these, from the dry- 

 ing up of the springs by which they were fed, have now run dry, and 

 others have lost a large share of their water supply — as, for example 

 the aqueduct aqua vergine (some 20,000 metres, or between 60 and 70 

 feet, long), which it is now in contemplation, at extraordinary expense, 

 to reconstruct. 



" The springs and aqueducts which, at one time, provided for the 

 City of ConstantiAople a very abundant supply of water for drinking 

 and for use, have fallen off to a very considerable extent in their pro- 

 ductiveness, so that it has become necessary to seek out more, and 

 more remote, springs. 



" The world-wide renowned fountains and water-works of Versailles 



