170 EFFECTS OF FOBESTS ON SPKINGS. 



pond owes its existence to a stream that has its source in the hills 

 which stretch some miles to the south. Within the time mentioned, 

 these hills, which were clothed with a dense forest, have been almost 

 entirely stripped of trees ; and to the wonder and loss of the mill- 

 owners, the water in the pool has failed, except in the season of 

 freshets ; and, what was never heard of before, the stream itself has 

 been entirely dry. Within the last ten yeai's a new growth of wood 

 has sprung up on most of the land formerly occupied by the old 

 forest ; and now the water runs through the year, notwithstanding 

 the great droughts of the last few years, going back from 1856.' 



" Dr Piper quotes from a letter of William C. Bryant the following 

 remarks : * It is a common observation that our summers are be- 

 coming drier and our streams smaller. Take the Cuyahoga as an 

 illustration. Fifty years ago large barges loaded with goods went up 

 and down that river, and one of the vessels engaged in the battle of 

 Lake Erie, in which the gallant Perry was victorious, was built at 

 Old Portage, six miles north of Albion, and floated down to the lake. 

 Now, in an ordinary stage of the water, a canoe or skiff can hardly 

 pass down the stream. Many a boat of fifty tons burden has been 

 built and loaded in the Tuscarawas, at New Portage, and sailed to 

 New Orleans without breaking bulk. Now the river hardly affords a 

 supply of water at New Portage for the canal. The same may be 

 said of other sti-eams — they are drying up. And from the same cause 

 — the destruction of our forests — our summers are growing drier and 

 our winters colder.' 



" Becquerel and other European writers adduce numerous other 

 cases where the destruction of forests has caused the disappearance of 

 springs, a diminution in the volume of rivers, and a lowering of the 

 level of lakes, and in fact, the evidence in suppprt of the doctrine I 

 have been maintaining on this subject seems to be as conclusive as 

 the nature of the case admits. We cannot, it is true, arrive at the 

 same certainty and precision of result in these inquiries as in those 

 branches of physical research where exact quantitative appreciation 

 is possible, and we must content ourselves with probabilities and 

 approximations. We cannot possibly affirm that the precipitation in 

 a given locality is increased by the presence, or lessened by the 

 destruction, of the forest, and from our ignorance of the subterranean 

 circulation of the waters, we cannot predict, with certainty, the dry- 

 ing up of a particular spring as a consequence of the felling of the 

 wood which shelters it; but the general truth, that the flow of 

 springJJ and the normal volume of rivers rise and fall with the exten- 



