18b9-90. I NATURAL HISTORY OF GROUND WATERS. 151 



Ontario, there is the general incline of strata from the central plateau 

 south-westerly. At Woodstock, at St. Mary's, at London, at Thames- 

 ville, at Chatham, and indeed all along the westerly part of this region, 

 there is evidence of the enormous body of water flowing westerly from 

 the higher ground to the east and north in the presence of artesian or 

 flowing wells in greater or less degrees according to the accidental height 

 of the soil as compared with the general level of the locality. 



On the other hand, as an evidence of topographical influences, we have 

 the fact that along the ridge of gravel which runs for many miles east 

 and west along Lake Erie, at times touching the lake, at others being 

 several miles away, and broad enough to have located upon it such towns 

 as Ridgetown, Blenheim, etc., numerous springs may be seen issuing 

 from either slope, in places only a hundred or so yards apart, those to 

 the south flowing into the lake, the others tending towards the valley of 

 the Thames some ten miles away. 



To give but one other illustration, a gentleman who resided at Norway 

 (near Toronto) for several years informed me that an old well had there 

 been sunk in the sandy soil some fifteen feet and gave a fair supply of 

 water. Its location being inconvenient to the house, he had another well 

 sunk nearer, and within one hundred yards of the other well, and he had 

 to go down some sixty feet in blue clay before what was probably the 

 same bed of sand was reached : it yielded abundant water. 



We have already referred to the source of subterranean waters as 

 being due to the rain falling upon the soil, and to the fact that a large 

 portion of the rainfall finds its way to the water-courses without being 

 absorbed by the soil. The balance, however, probably amounting to 

 about 50 per cent, of the total rainfall, is absorbed, but in very unequal 

 amounts. The amount of absorption, as will readily be understood, will 

 depend upon, first, the inclination of the surface soil, and second, on its 

 pervious or absorbent character. Setting the first aside as unavoidable, 

 we have to realize that the surface soil of Ontario with deforesting 

 and cultivation, has lost in large measure the virgin mould made up of 

 decaying vegetable matter which, loose in its character, absorbs in large 

 degree all the rain which falls upon it. This not only gives the underly- 

 ing soil every opportunity of absorbing all the moisture it can hold, but 

 also maintains it in a friable condition very difTerent from the hard-baked 

 surface which any one may notice even in sandy soils, which are exposed 

 to the heat of the sun. Accepting, however, existing conditions, it will 

 be seen that notable differences exist between the absorptive powers of 

 argillaceous and arenaceous soils and the various gradations between 

 them. We must here note a distinction of much importance in its bear- 



