A versatile solenoid. Its large size allows for more applications than smaller solenoids and can be used with a cathode ray tube or current balance. Heavy enamel #16 niclad copper wire is carefully wound on a tough phenolic core. The coil has 570 turns, and the wire ends at easy-to-use binding posts on the rigid plastic end plates. It can carry 10 amps intermittently and 5 amps continuously without overheating. Includes instructions and experiments. Solenoid is 15 cm long, 9 × 9-cm ends and large 6-cm interior diameter.