5 oS 



POPULAR SCIENCE MONTHLY 



The Tiny Rill of a Spring that has already developed a Small Basin. 



of the Black Hand formation, which borders the floodplains of all the 

 valleys, a distribution made possible because the formation has an 

 eastern dip of about twenty-five feet per mile. The springs in the 

 Black Hand are numerous and copious, partly because of the thickness 



The Black Hand Formation is generally a coarse, irregularly bedded sandstone, yie.ding 

 a copious supply of spring water. 



