Historical Torsion Balance Experiment - Coulomb’s Law Demonstration Apparatus #184555 (License: Personal Use)

This detailed line drawing depicts a torsion balance, famously employed by Coulomb in 1785 to quantify the inverse-square law of electrostatic attraction and repulsion. The device consists of a horizontal insulating rod suspended by a thin fiber inside a glass bell jar to eliminate air currents, with a small charged sphere at one end and a counterweight at the other; rotation is measured via a graduated scale on the base. Adjustable leveling screws ensure precise alignment for reproducible experimental results.

Used in physics education and museum exhibits to illustrate foundational electromagnetism experiments; targets students, educators, and history-of-science enthusiasts seeking visual understanding of early quantitative electrical measurements.