till not a picture in the Vatican was more vivid than his recollection.  He had gone with the Indian hunters to Niagara, and there, again, had flung his hopeless pencil down the precipice, feeling that he could as soon paint the roar as aught else that goes to make up the wondrous cataract.  In truth, it was seldom his impulse to copy natural scenery except as a framework for the delineations of the human form and face instinct with thought, passion or suffering.  With store of such his adventurous ramble had enriched him.  The stern dignity of Indian chiefs, the dusky loveliness of Indian girls, the domestic life of wigwams, the stealthy march, the battle beneath gloomy pine trees, the frontier fortress with its garrison, the anomaly of the old French partisan bred in courts, but grown gray in shaggy deserts,—­such were the scenes and portraits that he had sketched.  The glow of perilous moments, flashes of wild feeling, struggles of fierce power, love, hate, grief, frenzy—­in a word, all the worn-out heart of the old earth—­had been revealed to him under a new form.  His portfolio was filled with graphic illustrations of the volume of his memory which genius would transmute into its own substance and imbue with immortality.  He felt that the deep wisdom in his art which he had sought so far was found.

But amid stern or lovely nature, in the perils of the forest or its overwhelming peacefulness, still there had been two phantoms, the companions of his way.  Like all other men around whom an engrossing purpose wreathes itself, he was insulated from the mass of humankind.  He had no aim, no pleasure, no sympathies, but what were ultimately connected with his art.  Though gentle in manner and upright in intent and action, he did not possess kindly feelings; his heart was cold:  no living creature could be brought near enough to keep him warm.  For these two beings, however, he had felt in its greatest intensity the sort of interest which always allied him to the subjects of his pencil.  He had pried into their souls with his keenest insight and pictured the result upon their features with his utmost skill, so as barely to fall short of that standard which no genius ever reached, his own severe conception.  He had caught from the duskiness of the future—­at least, so he fancied—­a fearful secret, and had obscurely revealed it on the portraits.  So much of himself—­of his imagination and all other powers—­had been lavished on the study of Walter and Elinor that he almost regarded them as creations of his own, like the thousands with which he had peopled the realms of Picture.  Therefore did they flit through the twilight of the woods, hover on the mist of waterfalls, look forth from the mirror of the lake, nor melt away in the noontide sun.  They haunted his pictorial fancy, not as mockeries of life nor pale goblins of the dead, but in the guise of portraits, each with an unalterable expression which his magic had evoked from the caverns of the soul.  He could not recross the Atlantic till he had again beheld the originals of those airy pictures.