Opisometer Geology Used to draw electrons from

Used to draw electrons from glass and ebonite rods during rubbing

sized to read one step up from the 0-1A meter when student circuits draw past the lower meter's full-scale deflection

and field magnet for direct observation as students trace how current produces rotation in a closed magnetic circuit

Single large transparent plate filled with iron-rod plotting compasses

sized for beginner circuit and physics labs

Opisometer Geology Used to draw electrons fromOpisometer with a knurled wheel on a threaded spindle, rolling along curved lines on maps, charts, and drawings to convert winding distance into straight line length for geography coursework.