This screen electroscope is used to demonstrate the effect of surface curvature on the strength of an electric field. A characteristic of conducting objects at electrostatic equilibrium is that electric fields are strongest at locations along the surface where the object is most curved. The curvature of a surface can range from absolute flatness on one extreme to being curved to a blunt point on the other extreme. This electroscope has a flexible conductive fabric the is joined by 3 insulated metal pillars. The pillars can be manipulated to change the surface curvature of the fabric. When charged, the red strings embedded in the fabric will deflect. The degree of deflection will depend on how the fabric is situated (straight line vs curved). The use of a portable Van De Graaff generator (Fun Fly Stick) is the recommended charging method. A regular Van De Graaff generator will also work with proper setup.