Nor were the open spaces between these rocky mounds less remarkable.  In one valley, the course of a river which vanished ages ago, the power of fire had left its monuments amid those of the power of water.  The sedimentary rock of sandstone, shales, and marl, not only showed veins of ignitible lignite, but it was pierced by the trap which had been shot up from earth’s flaming recesses.  Dikes of this volcanic stone crossed each other or ran in long parallels, presenting forms of fortifications, walls of buildings, ruined lines of aqueducts.  The sandstone and marl had been worn away by the departed river, and by the delicately sweeping, incessant, tireless wings of the afreets of the air, leaving the iron-like trap in bold projection.

Some of these dikes stretched long distances, with a nearly uniform height of four or five feet, closely resembling old field-walls of the solidest masonry.  Others, not so extensive, but higher and pierced with holes, seemed to be fragments of ruined edifices, with broken windows and shattered portals.  As the trap is columnar, and the columns are horizontal in their direction, the joints of the polygons show along the surface of the ramparts, causing them to look like the work of Cyclopean builders.  The Indians and Mexicans of the expedition, deceived by the similarity between these freaks of creation and the results of human workmanship, repeatedly called out, “Casas Grandes!  Casas de Montezuma!”

It would seem, indeed, as if the ancient peoples of this country, in order to arrive at the idea of a large architecture, had only to copy the grotesque rock-work of nature.  Who knows but that such might have been the germinal idea of their constructions?  Mrs. Stanley was quite sure of it.  In fact, she was disposed to maintain that the trap walls were really human masonry, and the production of Montezuma, or of the Amazons invented by Coronado.

“Those four-sided and six-sided stones look altogether too regular to be accidental,” was her conclusion.  Notwithstanding her belief in a superintending Deity, she had an idea that much of this world was made by hazard, or perhaps by the Old Harry.

In one valley the ancient demon of water-force had excelled himself in enchantments.  The slopes of the alluvial soil were dotted with little buttes of mingled sandstone and shale, varying from five to twenty feet in height, many of them bearing a grotesque likeness to artificial objects.  There were columns, there were haystacks, there were enormous bells, there were inverted jars, there were junk bottles, there were rustic seats.  Most of these fantastic figures were surmounted by a flat capital, the remnant of a layer of stone harder than the rest of the mass, and therefore less worn by the water erosion.

One fragment looked like a monstrous gymnastic club standing upright, with a broad button to secure the grip.  Another was a mighty centre-table, fit for the halls of the Scandinavian gods, consisting of a solid prop or pedestal twelve feet high, swelling out at the top into a leaf fifteen feet across.  Another was a stone hat, standing on its crown, with a brim two yards in diameter.  Occasionally there was a figure which had lost its capital, and so looked like a broken pillar, a sugar loaf, a pear.  Imbedded in these grotesques of sandstone were fossils of wood, of fresh-water shells, and of fishes.