Opisometer Geology this concave glass mirror at

this concave glass mirror at 100mm focal length runs at f/1 for vivid real-image demos and converging-reflection work

supplying a duplicate-value option for paired-bench experiments on capacitor energy storage

Used to draw electrons from glass and ebonite rods during rubbing

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

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

Opisometer Geology this concave glass mirror atOpisometer 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.