324i A Dijfertation on the 



Streams, v/ells, and fountains are fulleft in the Spring. 

 In the Autum, many of them are abfolutely dried up. 



Thefe facts collectively prove, that the quantity of 

 water depolited on mountains is very great ; that they 

 are well qualified to retain it for the fupply of Springs j 

 and that fprings and rivers are all of them in part, and 

 many of them wholly, fupplied from this fource. 



Various objections are urged againft this theory. 

 The lirft is that water will not foak far enou2:h into 

 the ground. M. De La Hire, a French Philofopherjto 

 prove this, tried the following experiment. He dug a 

 hole in the lower terrace of the Obfervatory at Paris ; 

 and placed therein, eigh feet under ground, a large 

 leaden bafon, inclined a little towards one of its an- 

 gles. To this vi^as foldered a pipe, 1 2 feet long ; which, 

 after a confiderable defcent, reached into an adjoining 

 cellar. He then filled up the hole with a mixture of 

 fand and loam. After having kept the bafon, in this 

 fituation, \5 years, (the ground being conftantly ex- 

 pofed to all the rains and fnows that fell,) he rould 

 never obferve that a fingle drop of water had paffed 

 through the pipe into the bafon. 



On this fubject, I will make two remarks. 1st. Wa- 

 ter will certainly filter down^ as eafily as it will filter up ; 

 The attraction between the fand and the water is in each 

 cafe the fame; and in filtering down, it has the very fe- 

 rious affiftance of Gravity. If then, it will filter upwards 

 many miles, it will certainly filter downwards eight 

 feet. 2dly. Our own eyes teach us, that deep wells 

 frequently fail in dry weather ; and that wells which are 

 SO or 40 feet deep are often very obvioufly raifed by 

 the hard rain of a fingle night. Hence I am led to con- 

 clude, either that the pipe employed in the experiment 

 became clogged ; or that Providence knows how to 

 arrange earth, for the paffage of water through it, bet- 

 ter than M. De La Hire. 



It is likewife objected that fprings often rife on plains, 

 and fometimes on the fummits of hills. Such occur- 

 rences are uncommon. Of the few Springs which I 



