The catenary as Roulette.
2012 - J. Sanchez-Reyes
The College Mathematics Journal 43, 216 - 219 (2012)
The focus of a parabola rolling without sliding along a straight line traces a catenary. We give some historical notes on this classical kinematical construction, observe that it was rediscovered in a recent article, and give a simpler and more geometric alternative derivation.