Potential contour map of finite uniform cylinder. Same as Fig. 25 but for a finite uniform cylinder of the radius a = 1 and the half height c = 1. Namely, the object occupies the volume defined as 0 ≤ R ≤ a and 0 ≤ |z| ≤ c. The contours are drawn at every 2 per cent level of the bottom value. Easily visible is the non-analyticity of the potential on the surface of the cylinder, R = a and/or |z| = c. The map is not symmetric with the 90° rotation.