is no separation between Marble Canyon and the following one, the Grand Canyon, except the narrow gorge of the Little Colorado, so that topographically the chasm which begins at the Paria, ends at the Grand Wash, a distance of 283 miles, as the river runs, the longest, deepest, and altogether most magnificent example of the canyon formation to be found on the globe.  With an average depth of about four thousand feet, it reaches for long stretches between five thousand and six thousand.  At the Paria (Lee’s Ferry) the altitude above the sea is 3170 feet, while at the end of the canyon, the Grand Wash, the elevation is only 840 feet.  The declivity is thus very great (see the diagram on page 57, which gives from the Little Colorado down), the total fall being 2330 feet.  Further comment on the character of the river within this wonderful gorge is unnecessary.  Powell had been through it on his first expedition, and was now to make the passage again, to examine its geological and geographical features more in detail.  Meanwhile, as recorded in the last chapter, Lieutenant Wheeler had made an effort, apparently to forestall this examination, and had precariously succeeded in reaching Diamond Creek, which is just at the south end of the Shewits Plateau, lower left-hand corner of the map facing page 41.  Powell and Thompson arrived at our camp at the mouth of the Paria on the 13th of August (1872) accompanied by Mrs. Thompson, who had been at Kanab all the previous winter, and had pluckily made several trips with Thompson into the mountains, and Professor De Motte.  They had come in by way of the south end of the Kaibab, and it was on this occasion that the valley on the southern part of the summit was named De Motte Park.  Preparations for our descent through the great chasm were immediately begun.  The boats had been previously overhauled, and as the Nellie Powell was found unseaworthy from last season’s knocks, or at least not in condition to be relied on in the Grand Canyon, she was abandoned, and Lee kept her for a ferry-boat.  Perhaps she might have been repaired, but anyhow we had only men enough to handle two boats.  Steward’s trouble had not sufficiently improved to warrant his risking further exposure, so he had returned to his home in Illinois.  Bishop was in a similar plight, and went to Salt Lake to regain his health, and Beaman had started off to carry on some photographic operations of his own.  He came to the river and crossed on his way to the Moki country, while we were preparing to depart from the Paria.  Johnson and Fennemore, who had been with us part of the winter, were too ill to think of entering the great canyon, with all the uncertainties of such a venture, and as before noted they, too, had left.  Our party, then, consisted of seven:  Powell, Thompson, Hillers, Jones, W. C. Powell, Hattan, and Dellenbaugh, all from the first season’s crew.  No one else was available, as the trip was regarded in that region as extremely desperate.  On the l4th, the boats, Emma Dean