When Caltech’s former Sloan Lab reopened in January 2019 as the Linde Hall of Mathematics and Physics, staff, faculty, and students encountered a structure with a transformed interior that was originally built 97 years ago. Over the course of a century, it has witnessed many changes, evolving to suit the needs of the disciplines it has served: physics, mathematics, and electrical engineering. In its earliest years, the building was known by several names, including Edison High Tension Laboratory and High Voltage Research Laboratory, but was generally referred to as High Volts. It came into being out of a partnership between Caltech and the Southern California Edison (SCE) company, which contributed money to its construction in exchange for use of it for research. SCE had recently decided to change its transmission lines from 150,000 to 220,000 volts. The lines and associated equipment would need to be able to withstand a massive surge if they were struck by lightning, so SCE wanted to conduct research at a million volts, a higher voltage than could be reliably produced by any existing American laboratory.