In a series of projections along a wall, the _projections_ are taken as the unit, even when they almost meet at the top of the alternate space. When they actually do meet at the top, the enclosed space becomes the unit instead. These questions and others similar might be experimented upon, and examples of their treatment analyzed, as in the previous questions discussed. [Illustration: PLATE V.] FOOTNOTES: [Footnote 86: Stratton: Eye-Movements and Æsthetics of Visual Forms, Philosophische Studien, vol. 20, p. 350, 1902.] [Footnote 87: MacDougall: Structure of Simple Rhythm Forms, Harvard Psych. Studies, vol. 1, p. 321, 1903.] [Footnote 88: MacDougall: Structure of Simple Rhythm Forms, _ibid._ p. 322.] [Footnote 89: MacDougall: Structure of Simple Rhythm Forms, _ibid._ p. 322.] [Footnote 90: MacDougall: Structure of Simple Rhythm Forms, p. 325.] [Footnote 91: Bolton: American Journal of Psychology, p. 223, 1894.] [Footnote 92: Külpe: Outlines of Psychology, p. 395.] [Footnote 93: MacDougall: Structure of Simple Rhythm Forms, p. 348.] [Footnote 94: MacDougall: Structure of Simple Rhythm Forms, p. 349.] [Footnote 95: Stetson: Rhythm and Rhyme, Harvard Psychological Studies, vol. 1, p. 455, 1903.] [Footnote 96: Stetson: Rhythm and Rhyme, Harvard Psychological Studies, vol. 1, p. 455, 1903.] [Footnote 97: MacDougall: Structure of Simple Rhythm Forms, p. 377.] [Footnote 98: Perrot and Chipiez: Art in Ancient Egypt, p. 100.] [Footnote 99: Perrot and Chipiez: Art in Assyria and Chaldea, p. 126.] [Footnote 100: Perrot and Chipiez: Art in Persia.] THE FEELING-VALUE OF UNMUSICAL TONE-INTERVALS BY L. E. EMERSON