Another series of discoveries examined by Burke includes Eastman Kodak's Brownie, the disappearing elephant scare of 1867, billiard balls, celluloid as a substitute for ivory, false teeth that explode, gun cotton, double shot sound of a bullet, Mach's shock wave, aerodynamics, nuclear bombs, Einstein's relativity, Einstein's selenium, movie talkies, the vacuum tube amplifier, radio, railroad's use of wood, coal tar, gas lights, creosote, rubber, the Zeppelin, the automobile, and finally how Adeline vulcanises tires.