Plane curves that generally wind around a point while moving ever farther from the point. Many kinds of spiral are known, including the ancient Greek Archimedean spiral, described in On Spirals (ca. 225 BCE), and the logarithmic or equiangular spiral first described by René Descartes in 1638. The curves are observed in nature, and humans have used them in machines and in ornament, notably architecture, for example, the whorl in an Ionic capital. Prefer "scrolls (motifs)" or "scrollwork" for more complex forms.