抄録
Objects are real walls; height 2.5m×breadth 2.5m, h. 2.5m×b. 5.0m, h. 2.5m×b. 7.5m, h. 2.5m×b. 10.0m. Observation distances are 1.0m, 2.5m, 4.0m, 7.0m. Observation inclinations are 22°30', 45°, 67°30', 90°. Binocular vision. Rubber drawing method. Outdoor expeiment. Conclusions are; 1. Z is unvariable through breadth of wall. 2. Mean of Z≒0.6 3. The larger observation distance, the smaller degree of constancy. 4. When 2.5m×2.5m is observed at the points of large distance and large inclination, Z of g are very small, even sometimes minus. 5. These conclusions, except 4, are generally the same as those of other experiments.
