440 HYDROSTATIC PRESSURE EXEMPLIFIED 



just emerged Scamander. The channel that conducts the stream into 

 the basin is a cleft in the rock towards the right, only about four feet 

 wide and nearly twenty in height; it winds inwards in a curve, and 

 is soon lost in darkness ; at its bottom glides the current, which for a 

 few moments seems to repose in the basin beside, and then, by another 

 subterraneous channel, rushes to the mouth, from whence it issues to 

 the day : it here bursts from the precipice, and forms a noble water- 

 fall between forty and fifty feet high, broken, and furnished with 

 every accompaniment that the admirer of picturesque beauty could 

 require : its sides are fringed with pine and brushwood ; below, it is 

 almost hidden from the view by immense fragments of rock that have 

 fallen from the precipice ; and above it hang crags of from two to 

 three hundred feet in height, that jut over the bases in large angular 

 prominences. Such is the spring which flows through the sweet 

 vale of Menderi in many a winding turn. Far above this is the 

 summit of Ida the snowy head of Khasdag, the seat of the immortals 

 from whence the bard of yore could view Mysia, the Propontis, the 

 Hellespont, the JEgean sea, Lydia, Bythynia, and Macedonia. 



562. If sea water, which is nauseous to taste, and of perceptible 

 smell, be the constituent condition of the fluid we call water, then rain 

 water, which is without smell and taste, is salt water distilled by the 

 atmosphere; and this is the common quality of rain, river, and 

 spring water, except where accidental varieties of this last occur, 

 distinguished by the physical qualities of taste, odour, colour, and 

 temperature. 



563. Two constructions in the physical constitution of the earth 

 contribute to originate springs, which from the same circumstances 

 never cease to flow : one is the adaptation of the atmosphere to 

 transport water from the sea to high lands ; and the other is, the 

 porous beds of sand, and stone, and clay, which exert a capillary 

 influence in conveying the fluids they may be charged with from one 

 elevation to another. Those beds or strata of sand and stone, 

 resemble sponge, paper, or pipes, as conductors of fluids that are 

 heavy and incompressible, as water; clay strata, which are impe- 

 netrable by water, form the great reservoirs or basins in which the 

 treasure of the skies lies hid. Dislocations in the general mass, 

 resulting from fractures, intersect the strata and facilitate the dis- 

 charge from the reservoirs formed by the clay stratum. 



564. The water-bearing strata are at various depths, from 50 to 500 

 feet below the surface, and a sheet of impure, or mineral water, may 

 be perforated till the operation conducts to a stratum containing pure 



