I'm trying to draw a logarithmic spiral by hand (actually I need to use a plotter to cut a spiral on wood, but that is another story) and I saw this method:
http://www.wikihow.com/Draw-A-Perfect-Spiral
it seems to me like a log spiral, because, if precisely done, the distance to the center is shortened geometrically.
Let me know if I'm correct!.
Thanks!.
I believe that that is an Archimedian Spiral. Each time it goes around, its shortens by the circumference of the pencil. This arithmetic decreasing is not logarithmic at all.
For more info about drawing and recognizing spirals, see http://en.wikipedia.org/wiki/Spiral