Mary Hallock-Greenewalt

Book excerpt: Mary Hallock-Greenewalt played the piano with the Philadelphia and Pittsburgh Orchestras as a concert soloist, invented her own color organ that she called a "Sarabet" after her mother, and, in her pursuit of the art she named "Nourathar" by combining the Arabic words for "essence of light,"she had to invent the machinery required as well. Numbered among her inventions are the rheostat that allos the gradual fading of light, the mercury switch, and was among the earliest developers of colored gel filters for tinting theatrical lights. Her patent for the rheostat became the subject of an infirngement lawsuit in the lat 1920s against such large corporations as General Electric, a lawsuit that she ultimately won in 1936. This volume collects all eleven of her technology patents, revealing the refinement and evolution of the Sarabet. These patents also enable a clear evaluation of her contributions to visual music, since, as Dr. Betancourt notes in his introduction, the patents allow a much clearer determination of her place in history and a peer-reviewed statement of her accomplishments.