The evolute spiral angle is a wave pattern that mimics the wave of the sea.
Meyer, Franz Sales Handbook of Ornament (New York, NY: The Bruno Hessling Company, 1904)
TIFF (full resolution)
2241×2400, 359.5 KiB
Large GIF
956×1024, 67.4 KiB
Medium GIF
597×640, 38.9 KiB
Small GIF
298×320, 15.7 KiB