Captain Jack’s cave is one of the many somber cells of the castle.  It measures twenty-five or thirty feet in diameter at the entrance, and extends but a short distance in a horizontal direction.  The floor is littered with the bones of the animals slaughtered for food during the war.  Some eager archaeologist may hereafter discover this cabin and startle his world by announcing another of the Stone Age caves.  The sun shines freely into its mouth, and graceful bunches of grass and eriogonums and sage grow about it, doing what they can toward its redemption from degrading associations and making it beautiful.

Where the lava meets the lake there are some fine curving bays, beautifully embroidered with rushes and polygonums, a favorite resort of waterfowl.  On our return, keeping close along shore, we caused a noisy plashing and beating of wings among cranes and geese.  The ducks, less wary, kept their places, merely swimming in and out through openings in the rushes, rippling the glassy water, and raising spangles in their wake.  The countenance of the lava beds became less and less forbidding.  Tufts of pale grasses, relieved on the jet rocks, looked like ornaments on a mantel, thick-furred mats of emerald mosses appeared in damp spots next the shore, and I noticed one tuft of small ferns.  From year to year in the kindly weather the beds are thus gathering beauty—­beauty for ashes.

Returning to Sheep Rock and following the old emigrant road, one is soon back again beneath the snows and shadows of Shasta, and the Ash Creek and McCloud Glaciers come into view on the east side of the mountain.  They are broad, rugged, crevassed cloudlike masses of down-grinding ice, pouring forth streams of muddy water as measures of the work they are doing in sculpturing the rocks beneath them; very unlike the long, majestic glaciers of Alaska that riverlike go winding down the valleys through the forests to the sea.  These, with a few others as yet nameless, are lingering remnants of once great glaciers that occupied the canyons now taken by the rivers, and in a few centuries will, under present conditions, vanish altogether.

The rivers of the granite south half of the Sierra are outspread on the peaks in a shining network of small branches, that divide again and again into small dribbling, purling, oozing threads drawing their sources from the snow and ice of the surface.  They seldom sink out of sight, save here and there in the moraines or glaciers, or, early in the season, beneath the banks and bridges of snow, soon to issue again.  But in the north half, laden with rent and porous lava, small tributary streams are rare, and the rivers, flowing for a time beneath the sky of rock, at length burst forth into the light in generous volume from seams and caverns, filtered, cool, and sparkling, as if their bondage in darkness, safe from the vicissitudes of the weather in their youth, were only a blessing.