our own period compared with that of Egypt and Judea.  It is mainly these later formations—­the Permian, the Jurassic, the Triassic, the Cretaceous, the Eocene,—­that give the prevailing features to the South-western landscape that so astonish Eastern eyes.  From them come most of the petrified remains of that great army of extinct reptiles and mammals—­the three-toed horse, the sabre-toothed tiger, the brontosaurus, the fin-backed lizard, the imperial mammoth, the various dinosaurs, some of them gigantic in form and fearful in aspect—­that of late years have appeared in our museums and that throw so much light upon the history of the animal life of the globe.  Most of the sedimentary rocks of New York and New England were laid down before these creatures existed.

Now I am not going to write an essay on the geology of the West, for I really have little first-hand knowledge upon that subject, but I would indicate the kind of interest in the country I was most conscious of during my recent trip to the Pacific Coast and beyond.  Indeed, quite a geologic fever raged in me most of the time.  The rocks attracted me more than the birds, the sculpturing of the landscapes engaged my attention more than the improvements of the farms—­what Nature had done more than what man was doing.  The purely scenic aspects of the country are certainly remarkable, and the human aspects interesting, but underneath these things, and striking through them, lies a vast world of time and change that to me is still more remarkable, and still more interesting.  I could not look out of the car windows without seeing the spectre of geologic time stalking across the hills and plains.

As one leaves the prairie States and nears the great Southwest, he finds Nature in a new mood—­she is dreaming of canyons; both cliffs and soil have canyon stamped upon them, so that your eye, if alert, is slowly prepared for the wonders of rock-carving it is to see on the Colorado.  The canyon form seems inherent in soil and rock.  The channels of the little streams are canyons, vertical sides of adobe soil, as deep as they are broad, rectangle grooves in the ground.

Through all this arid region nature is abrupt, angular, and sudden—­the plain squarely abutting the cliff, the cliff walling the canon; the dry water-course sunk in the plain like a carpenter’s groove into a plank.  Cloud and sky look the same as at home, but the earth is a new earth—­new geologically, and new in the lines of its landscapes.  It seems by the forms she develops that Nature must use tools that she long since discarded in the East.  She works as if with the square and the saw and the compass, and uses implements that cut like chisels and moulding-planes.  Right lines, well-defined angles, and tablelike tops of buttes and mesas alternate with perfect curves, polished domes, carved needles, and fluted escarpments.

In the features of our older landscapes there is little or nothing that suggests architectural forms or engineering devices; in the Far West one sees such forms and devices everywhere.