Theremin recalled that while still in his last year of school, he had built a million-volt Tesla coil and noticed a strong glow associated with his attempts to ionise the air. He then wished to further investigate the effects using university resources. A chance meeting with Abram Fedorovich Ioffe led to a recommendation to see Karl Karlovich Baumgart, who was in charge of the physics laboratory equipment. Karl then reserved a room and equipment for Theremin's experiments. Abram Fedorovich suggested Theremin also look at methods of creating gas fluorescence under different conditions and of examining the resulting light's spectra. However, during these investigations Theremin was called up for World War I military service.