Hi. I'm looking for a "rivers of the world" scale data set, something for students to use, i.e. low-resolution is fine. Are there any free on-line sources? Adios, Chris -- C.S. Cornuelle School of Mathematics/MCIM, University of Minnesota 206 Church St. SE, Minneapolis, MN 55455 (612) 626-8930v, (612) 624-2333f, bob at math.umn.edu Ferventer Vestite