One of the puzzles of Grand Canyon, Bradshaw Mountains, and Searchlight--if not also of New England, the Black Hills, and the Yellowstone--is faulting. A fault is what a geologist means by a crack down deep where the country rock has dropped down on one side so as to make a discordance across country. Earthquake faults make a visible bank or step or sidewise slip, changing the surface after an earthquake. The northwestern states are partly mapped as fault block mountains. The island of Hawaii has a series of fault step blocks southeast, slipping toward the ocean. The steep east face of the Sierra Nevada is a fault fracture. Professor Shaler once stopped me on the street and said of my field work, “Jaggar, you don’t teach faulting enough.” Faults were shown along straight lines on the color maps of formation in the old Boston books, and were located by guesswork if glacier deposits covered up the ledges. It seemed to me that faults ought to be proved or else omitted from the maps. Probably I too was wrong, for faults or cracks completely concealed by soil and strata are tremendous unknown lines on the globe. The Searchlight ore body is certainly a fault fracture, and so are those of Tonopah and hundreds of mines. It was digging that proved it. The cracking and slipping and steaming and mud-making on the fissure are what brought up the minerals. A question arises as to how much the Grand Canyon itself and its tributaries are guided by fault fractures under valleys. My impression was in 1901, and it still is, that “Jaggar ought to teach faulting” more than he then did. The primitive ocean blocks of earth crust sank, while continents remained high, leaving the earth crust a mosaic of blocks large and small, high and low. Between the blocks spout the volcanoes. I have never agreed with C. E. Dutton that volcanic heat energy could come from shallow pockets under those fault blocks. Even he acknowledged the weakness of the argument. If the earth crust broke up and the blocks variously sank in the core matter, leaving continents as a complex of high blocks, then the blocks are deep and are still moving. The movements are in years, year-thousands and year-millions. Volcanism up the cracks releases core energy. So does much of fault movement, namely earthquakes. And these facts geologists do not appreciate. So we get faulted river courses and fault cracks up which came fluids that transformed sediments of rivers, lakes, deserts, and seas into granite, felsite, and greenstone. These are the ancient names. There are hundreds of other, geology names. But geology produced no Faraday.