Gravel Hill
| View Cart ⇗ | Info
“Suppose a to be a gravel hill, and b a strata of clay or rock, impervious to water. The fluid percolating through the gravel would reach the impervious strata, along which it would run until it found an outlet at c at the foot of the hill, where a spring would be formed.” — Wells, 1857
Source
David A. Wells The Science of Common Things; A Familiar Explanation of the First Principles of Physical Science51
Downloads
2400×747, 801.8 KiB
1024×318, 97.9 KiB
640×199, 47.0 KiB
320×99, 15.2 KiB