Jonas crawled stiffly out of his compartment.  Enoch began preparation for a fire, white the others busied themselves with notes and observations.  It was 90 degrees on the little sandy beach and the wet clothing was not chilling.  They ate enormously of Jonas’s dinner, then the Survey men scattered to their work for an hour or so, while Enoch explored the region.  There was no getting to the top of the walls, so he contented himself with crawling gingerly over the rocks to a point where a little spring bubbled out of a narrow cave opening.  Peering through this, Enoch saw that it was dimly lighted, and he crawled through the water.

To his astonishment, he was in a great circular amphitheater, a hundred feet in diameter, domed to an enormous height, with the blue sky showing through a rift at the top.  The little spring trickled down the wall, now dropping sheer in spray, now trickling in a delicate, glistening sheet.  But the greatest wonder of the cave was in the texture of its walls, which appeared to Enoch to be of purest marble of a deep shell pink and translucent creamy white.  Moisture had collected on the walls and each tiny globule of water seemed to hold a miniature rainbow in its heart.  There was a holy sort of loveliness about the spot, and before he returned to the rugged adventure outside, Enoch pulled off his hat and christened the place Diana’s Chapel.  Nor did he, on his arrival at the camp, tell of his find.

Shortly after two o’clock Milton ordered all hands aboard.  But before this he had shown them all the map, adding a rough sketch of his own.  The next rapid appeared to be no more dangerous than the previous one.  But below it the river widened out into a circular bay, a great tureen within which the waters moved with an oil-like smoothness.  But when Milton threw a stick into this strange basin, it was whirled the entire circumference of the bay with a velocity that all the men agreed boded ill for any boat that did not cling to the wall.  The west end of the bay, where it was all but blocked by the closing in of the Canyon sides, could not be seen from the rocks where the men stood.  But the old maps reported a steep fall which must be portaged.

“Cling to the right-hand wall,” ordered Milton.  “If you steer out, Harden, for the sake of the short cut, you may be lost.  The reports show that two other boats were lost here.  Cling to the wall!  When we reach the mouth we must go ashore again and examine the falls.  Be sure your life preservers are strapped securely.”

“Mr. Milton,” said Jonas, “you better let me get my hands on a oar.  If I got to die, I’m going to die fighting.”

“Good stuff, Jonas!” exclaimed Harden.  “Can you row?”

“Brought up on the Potomac,” replied Jonas.

“All right, folks,” cried Milton.  “We’re off.”