Barrel and Pincushion

One of the five basic optical aberrations is Distortion. Whether the Distortion aberration has a positive or negative sign determines whether it is described as “Pincushion” or “Barrel” distortion. The origin of the term “Barrel” distortion is obvious—the image of a square object produced by an optical system with negative distortion resembles a classic “barrel” shape. But one with a positive coefficient produces a shape that is not that of the pincushions of my acquaintance. What kinds of pincushions inspired the name of this characteristic aberration, and who came up with it?