Capacitance Substitution Box, Model 1137 Subcategory_Entomology Supplies demonstrating how a crane lifts

demonstrating how a crane lifts loads through the mechanical advantage of a large wheel turning a small axle

Fine-gauge 24 SWG bare copper wire on a 250g reel approximating 375 feet

suited to fieldwork in geography units and orientation activities outside the classroom

Slotted with a central well on each glass

supported on die-cast end pieces with a nickel-plated phosphor-bronze sliding contact

Capacitance Substitution Box, Model 1137 Subcategory_Entomology Supplies demonstrating how a crane liftsRotary dial capacitance substitution box, dropping a chosen capacitor into a circuit without unsoldering during introductory RC circuit and resonance investigations at the bench.