The exposition was lit in a new way, and the Scintillator was the flourish on top. W. D'A. Ryan of General Electric, put in charge of the exposition's Bureau of Illumination, avoided the old method of outlining buildings in bare bulbs. Instead masked floodlights washed the travertine walls, colors and sculpture, so the architecture was "as distinct by night as by day, and even more beautiful" (Todd). Direct lighting was kept for a few places, above all the Zone, with its festoons and colored lanterns. Ryan had already used scintillator displays at Niagara Falls in 1907 and New York's Hudson-Fulton Celebration (Wikipedia).
The Scintillator itself stood on "Moro Castle," a small mole projecting east from the northwest corner of the Yacht Harbor. It was 48 searchlights in two banks, each 36 inches across and fitted with changeable colored gelatin screens. Forty-eight Marines ran it in squads under four corporals, who took orders by telephone from a first sergeant and megaphoned them to the men. Across the harbor a locomotive stood on the fireworks pier to supply steam clouds, with a pierced steam-pipe standard beside it, and 275 steel mortars buried in sand fired bombs 500 ft into the air.
Three nights a week from 7:45 the program ran for an hour. Beams fanned into the southwest until they seemed to converge like railroad tracks, lit plumes of steam and smoke, crossed "in chromatic quadrilles" on the clouds rolling in the Golden Gate, and ended with an Aurora Borealis held for half an hour. The Guide's list of effects reads like a circus bill: the Beam Dance, Spook's Parade, Plumes of Paradise, Devil's Fan, Chromatic Wheels, Fairy Feathers.
Had anyone been looking this way from Mars he must have thought somebody had at least struck a match.
Frank Morton Todd, The Story of the Exposition, vol. 2, ch. LXIII (1921)