AETIFICIAL SPEESTGS. 469 



charged witli boracic acid, and other fortunate applications of the 

 heat of thermal sources, lend some countenance to the latter 

 project ; but both must, for the present, be ranked among the 

 vague possibiHties of science, not regarded as probable future 

 triumphs of man over nature. 



Artificial Sjprvngs. 



A more plausible and inviting scheme is that of the creation 

 of perennial springs by husbanding rain and snow water, storing 

 it up in artificial reservoirs of earth, and filtering it through 

 purifying strata, in analogy with the operations of nature. The 

 sagacious Palissy — starting from the theory that all springs are 

 primarily derived from precipitation, and reasoning justly on the 

 accumulation and movement of water in the earth — ^proposed to 

 reduce theory to practice, and to imitate the natural processes by 

 which rain is absorbed by the earth and given out again in run- 

 ning fountains. " When I had long and diligently considered 

 the cause of the springing of natural fountains and the places 

 where they be wont to issue," says he, " I did plainly perceive, 

 at last, that they do proceed and are engendered of nought but 

 the rains. And it is this, look you, which hath moved me to 

 enterprise the gathering together of rain-water after the manner 

 of nature, and the most closely according to her fashion that I am 

 able ; and I am well assured that by following the formulary of 

 the Supreme Contriver of fountains, I can make springs, the 

 water whereof shall be as good and pure and clear as of such 

 which be natural." * Palissy discusses the subject of the origin 

 of springs at length and with much ability, dwelling specially 

 on infiltration, and, among other tilings, thus explains the fre- 

 quency of springs in mountainous regions : " Having well con- 

 sidered the which, thou mayest plainly see the reason why there 



to a greater depth than the few yards at which we meet an invariable temper- 

 ature corresponding with the atmospheric mean. Hot water, then, whether 

 reached by artesian borings or rising from great depths in hot springs, is not 

 derived from precipitation conveyed downwards to a heated stratum by ordi- 

 nary filtration, but from lakes or rivers, by means of crevices or apertiu'es in; 

 the superficial crust of the earth, and where such crevices do not exist, little; 

 ■water will be found far below the surface. 

 * (Euvrea de Paiissy, Des Eaux et Fontaines, p. 157. 



