Arc Light Control


Arc Light Control




Lightning is the ultimate arc lamp, and so Benjamin Franklin's 1752 experiment of drawing electricity from the clouds and jumping a spark is perhaps the first arc lamp. In 1801 Humphry Davy observed the brilliant spark obtained when the connection between two carbon rods, attached to the poles of a battery, was broken. Some years later, in a demonstration lecture at the Royal Institution, he produced an arc nearly three inches in length. He used a voltaic battery with 2000 sets of plates, each four inches square. Commercial arc lighting had to wait for the development of dynamos such as the Gramme Machine in the early 1870s.


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“Arc Light Control,” Digital Exhibits at Washington and Lee University Library, accessed September 24, 2017,