Probably no two chapters of the earth's history differ more than those of the two sides of the Hudson at New York. There is a great break here--a leap from Archaean times on the east side to Mesozoic times on the west. The east side is millions of years the older. Here is the original Plutonic or Azoic rock which apparently has never been under the sea since it was first thrust up out of the fiery depths. The west shore, including the Palisades, belongs to a much later geologic era. The original granite here is buried under vast deposits of sedimentary rock of the Triassic age--the age of the giant reptiles, the remains of one of which has recently been found embedded in this sandstone, near the river's edge. As the traveler's eye follows along the even, almost level line of this escarpment of the Palisades, let it re-create for him the strata of the old Triassic sandstone that were millions of years ago piled high upon it,--how high can only be conjectured,--but which have been removed grain by grain under the eroding power of the forces of air and water that now seem to caress the huge wall so gently. Ah! geologic Time, what can it not do? what has it not done? The old sill of Vulcan now presents a nearly vertical front to the Hudson, forming the Palisades, showing that some leaves of the earth's history here are missing, buried probably beneath the waters of the river. There is evidently a line of fault here, and the west side has been lifted up out of the old Mesozoic seas, probably in the convulsions that poured out the lava of the trap rock. IX SCIENTIFIC FAITH I find myself accepting certain things on the authority of science which so far transcend my experience, and the experience of the race and all the knowledge of the world, in fact which come so near being unthinkable, that I call my acceptance of them an act of scientific faith. One's reason may be convinced and yet the heart refuse to believe. It is not so much a question of evidence as a question of capacity to receive evidence of an unusual kind. One of the conclusions of science which I feel forced to accept, and yet which I find very hard work to believe, is that of the animal origin of man. I suppose my logical faculties are convinced, but what is that in me that is baffled, and that hesitates and demurs?