The word that the Broadway stagehands strike by Local One of the International Alliance of Theatrical Stage Employees had been resolved in time for the late December holiday season was great news for theatergoers (the show must go on!). Among other exciting plays, readers of Today’s Engineer will now be able to see “The Farnsworth Invention.” Written by award-winning playwright Aaron Sorkin and starring well-know actors Hank Azaria and Jimmi Simpson, this new play tells–in fictionalized form–the story of Philo T. Farnsworth and David Sarnoff and their battles over the early development of television.
While it is exciting to see electrical engineering brought to the stage, because of the controversial nature of the history–and the difficulty of art capturing “truth”–this column will not be a review of the play. The production is receiving good press, and the reader is urged to see it for him- or herself. However, this is an opportunity to point out the importance of electrical engineering not just to theater content, but to theater infrastructure as well.
Even before the current age of smoke machines, strobe lights and other high-tech special effects, live theater had a challenge if it was held indoors away from the elements, how could it be lit in such a way that the action would appear somehow “natural”, and yet could be seen by an audience who were not at the natural distances and angles from the actors they would have been if they were part of the action in real life.
As early as 1585, the Teatro Olimpico in Vicenza, Italy, was lit by candles. Candles in theaters were eventually replaced by oil lamps and then by gas lights. None of these technologies, however, were sufficient to produce “specific illumination” that provides a sharp, highly controlled shaft of light. These shafts are used to highlight a small area of the stage or create the illusion of moonlight or sunlight. The problem was solved in 1816 with the invention of the limelight by Thomas Drummond, but the chemical nature of the lamp still led to problems with safety and comfort.
In 1807, Sir Humphrey Davy had demonstrated the carbon arc lamp, but its utility was limited by the available power sources (batteries made of voltaic cells). By the 1890s, the development of generator-powered carbon arc lamps by Charles Brush and others led to the carbon arc lamp beginning to replace limelight in theaters. By the 1920s, the incandescent lamp of Thomas Edison was able to achieve 1000-watt status, and that new technology began to replace arc lamps, while limelight disappeared altogether (although the term lives on!).
Meanwhile, in 1904, incandescent technology had allowed Louis Hartmann to build the first followspot, or spotlight (another term that entered the vernacular)–powerful stage light concentrated by a lens which can be controlled by a human operator to “follow” actors around the stage. It was first used in the Broadway production of “The Music Teacher” by the pioneering Broadway writer-director-producer David Belasco. A number of advances based on lens technology followed, most notably those by the Kliegl brothers (inventors of the eponymous klieg light, used in cinema and at rock concerts).
The flexibility provided by electric lighting to both general and specific illumination has enabled the modern theatrical experience, from the barest one-person play to a Disney extravaganza. There may be no business like show business, but there is no profession that enhances quality of life like the electrical engineering profession!