After President Garfield was shot in 1881, Alexander Graham Bell built a metal detector to find the bullet. It was based on an induction balance, a device that used a battery and coils: one coil was swept over the body, and when it passed over metal, a buzzer or earpiece gave a click. Bell had tested the device on Civil War veterans with known bullet locations. When he tried it on Garfield in July 1881, doctors kept asking him to scan only one area, and the metal bedsprings interfered with the readings. The bullet was never located, and Garfield died in September.

Hampi is a UNESCO World Heritage Site in Karnataka, India, with more than 1,600 surviving remains spread over 4,100 hectares. It was the capital of the Vijayanagara Empire from 1336 to 1565. Travellers from Persia and Portugal described it as a prosperous, wealthy and grand city with temples, markets and farms along the Tungabhadra River. By 1500 it was estimated to be the world's second-largest city after Beijing, and probably India's richest at the time. In 1565 a coalition of Muslim sultanates defeated the Vijayanagara Empire, its capital was conquered and destroyed, and the city was left in ruins. Hampi remains a religious centre, with the active Virupaksha Temple at its heart.