黒板画譜
Kokuban Gafu (黒板画譜), a 1902 Japanese illustrated manual by Ishihara Wasaburō and Ichijō Narimi, published by Shinseisha, presenting blackboard-style diagrams with white line drawings on black ground. The pictures show rows of circles, sperm-like and egg-like forms, and linked figures arranged in grids with equals signs, arrows, and tick-like marks. A designer might take from them the rhythm of repeated circles in ordered columns, and the stark white-on-black diagram language with its minimal lettering-free notation.
