During the Gjøa and Discovery expeditions (1901–1906), weak geomagnetic signatures were observed simultaneously with visual polar cap auroras.  Main types are transpolar arcs, poleward-moving substorm arcs, and Sun-aligned arcs.  The first two are infrequent, while the last one occurs often. They appear like the regular magnetic solar Sq variation.  It is suggested that they are embedded in polar rain and dependent on the density and energy of photoelectrons.