Spiral Small 319×320 Medium 639×640 Large 1022×1024 Download Tiff Original 2395×2400 | (411.6 KB) Description Illustration of a spiral curve. Keywords curve, spiral, spirals Galleries Spirals Source: Albert A. Hopkins Scientific America: Handy Book Of Facts And Formulas (New York: Munn & Co., Inc., 1918) 41
