Many of the structures which surround us in nature (mountains, rivers, coastlines, clouds, the vascular system and other biological structures, for example) and systems of scientific interest (aggregates, macromolecules, rough surfaces, “strange” attractors, etc.) cannot be adequately described in terms of the concepts of Euclidean geometry. The lack of a quantitative description of these structures has inhibited the development of adequate understanding of their formation and behavior. During the past 2–3 decades a new approach to the description of many of these systems has been developed.[1–3] This approach, now known as fractal geometry, has been shown to be relevant to a broad range of structures and phenomena of both scientific and practical importance.