Gradually, however, as the country expanded Westward and the pioneer spirit of the nation was aroused, American artists began to attempt bigger subjects. Church, Bierstadt, and Thomas Moran attacked the colossal wonders of the Yellowstone and the Rockies. It was no longer the beauty of nature that inspired them, so much as its marvelousness and immensity. As many people believe, they tried to do something that is beyond the power of painting to express. For on the comparatively tiny space of their canvasses they did succeed in expressing some of the appearances of nature’s grandeur, but they hardly made you feel it. I believe myself it is impossible that they should; for an artist can only make you feel in his picture something of what he himself has felt; and he must have thoroughly mastered his own feeling before he can express it. But in the presence of the stupendous works of nature, as far as my experience goes, the feeling masters ourselves. Amid the vastness of the height and depth and breadth and the grandeur and glory and marvel of it all, our spirit is swept out of us. We see the mighty volume of water coming over Niagara and hear the roar of its might; but not as we gaze into the face of a friend and listen to the voice that we have learned to know and love so well. In the one case our feeling is all brought to a center of attraction, in the other it is caught away and carried beyond our comprehension. We can only lose ourselves in wonder.