and much misgiving they drifted on between mile-high cliffs, rising terrace on terrace to the very sky itself.  Even now, when the dangers are known and tested, no man lives who can enter the great chasm for a voyage to the other end without feeling anxiety as to the result, and the more anxiety he feels, the more probability there is that he will pass the barriers safely.  Running rapids and passing falls by portages and let-downs, they met no formidable obstacle till August 14th, when they ran into a granite formation, the “First Granite Gorge.”  While the gorge was wide above, it grew narrower as the river level was approached, till the walls were closer than anywhere farther up; and they were ragged and serrated.  They had noticed that hard rocks had produced bad river, and soft rocks smooth water; now they were in a series of rocks harder than any before encountered.  There was absolutely no way of telling what the waters might do in such a formation, which ran up till a thousand feet of it stood above their heads, supporting more than four thousand feet more of sedimentary rocks, making a grand total of between five thousand and six thousand feet.  The same day on which they entered the granite they arrived, after running, and portaging around, several bad rapids, at a terrific fall, announced by a loud roar like the steady boom of Niagara, reverberating back and forth from wall to wall, and filling the whole gorge with its ominous note.  The river was beaten to a solid sheet of reeling foam for a third of a mile.  There was but one choice, but one path for the boats, and that lay through the midst of it, for on each side the waves pounded violently against the jagged cliffs which so closely hemmed them in.  Men might climb up to the top of the granite and find their way around the obstruction, one thousand feet above it, descending again a mile or two down, but they could not take the boats over such a road.  They must, therefore, run the place, a fall of about eighty feet in the third of a mile, or give up the descent.  So they got into their boats and started on the smooth waters, so soon shattered into raging billows.  Though filled with water, the boats all rode successfully and came out below crowned with success.  Often a rapid is greatly augmented by enormous boulders which have been washed into the river from some side canyon, and, acting like a dam, block the water up and cause it to roar and fret tenfold more.  Black and dismal is this granite gorge; sharp and terrible the rapids, whose sheeted foam becomes fairly iridescent by contrast.  The method of working around some of the worst places is illustrated well by the following extract: