Page:Tree Crops; A Permanent Agriculture (1929).pdf/65

 . 23. Top. Water-holding terraces made by machinery in clay hillside orchard of Lawrence Lee, inventor. This is one of the great inventions. The moisture substitute for cultivation is evident. (Courtesy J. R. Linter.)—. 24. Bottom. Three hybrid poplars from same parentage. Project by McKee, a chemist—quite a joke on the foresters. Some of these grow with great speed. (Courtesy Ralph McKee, A. B. Stout, and E. J. Schreiner.)