Laura Ackley, author of San Francisco’s Jewel City, will discuss the elaborate and ground-breaking lighting effects created for San Francisco’s Panama-Pacific International Exposition of 1915. The lighting effects included the Great Scintillator, the Tower of Jewels, and the Electric Kaleidoscope. A battery of forty-eight spotlights, collectively known as the Great Scintillator, were projected through colored gels into the famous San Francisco fog to form effects with such evocative names as “Devil’s Fan” and “Fighting Serpents and Octopus.” Specially designed, 2-inch cut glass “Novagems” were hung from the central Tower of Jewels to create a constant shimmering under the colored spotlights. Astronomical displays were projected onto the interior of the huge, glass dome of the Palace of Horticulture using a contraption called the Electric Kaleidoscope. Ackley will describe these spectacular effects, plus Ryan’s most lasting contribution to the practice of lighting design, the popularization of concealed light sources for architectural lighting.