The net effect of German scholarship on me was a feeling of irksomeness and resentment, but what I learned of thoroughness and of mechanisms I value extremely. I honor the memory of those teachers, and I honor their pupils, who by specialism have penetrated deeper and deeper into the smaller and smaller things of matter. The ultimate is the background material between the galaxies of the universe and the unknown background particles of life. But for me, the middle field--the development of mountains, rivers and sea bottoms, continents and volcanoes, earthquakes and depressions of land, the sky, clouds, and waters--all the outside world, needed experimental engineers. Intermediate bigger things like the crust of the earth and moon, within the time that is measured in human years, seemed to be neglected by science, and yet to be accessible to the giant power of engineering. Rosenbusch set me at one feldspar specimen for an entire summer. I wanted things moving, changing, and evolving. I wanted a narrative of that tabular feldspar crystallizing, or better, a dish wherein to watch it crystallize. To me it seemed that Faraday or Pasteur would have described the quality of a moving feldspar medium in pressure, heat, gas, liquid, or changing particles. The qualitative investigator would have a furnace and make many trials and produce synthetic feldspar, and he would write a narrative approximating what the under earth must do. He would make melt or froth conditions successful in imitating such rocks as basalt or granite, using hot gases. The problem of basalt and granite began to be recognized in the eighteenth century. Werner guessed, and taught his pupils, that these rocks were sea bottom deposits. A few determined Europeans in the nineteenth century--Fouqué and Michel-Lévy, Doelter, and Morozewicz--melted mineral mixtures and made igneous rocks by cooling them. The motive was approximation; the result was good and useful. No one reached melting by hot gases and absorption of hot gases. No one made granite. Volcanic rocks were imitated approximately as to crystals, but not as to gases. And the whole of volcanism was later proved to be gases, as is the whole of physics and astronomy and biology. Man is largely a puff of hydrogen. These visions were what I brought back from Europe, along with much pondering of such experimenters as Daubrée, Lacroix, Stanislas Meunier, Reyer, and my teacher Goldschmidt, all brilliant imitators of the earth. Goldschmidt gave a course in blowpipe analysis which was completely original. His methods went far beyond those of his predecessors. Meanwhile, W. M. Davis had written me to come home to Harvard and give the course in field geological surveying. This was in 1895–1896.