Edison’s first successful electric lamp
The electric light was not invented by Thomas Edison. In fact in the years preceding Edison’s invention, electric light was somewhat common in the form of electric arc lamps that were in use in factories, or to light up the town square.
The light from an arc lamp is produced by passing a large current between the electrodes (usually carbon) of the lamp. The result is a very intense light, accompanied by the sounds and smells of the burning arc. While the arc lights did produce much brighter light than the gas lamps of the day, they required a huge amount of power to operate and were nearly blinding in their intensity – certainly not usable in the home or office.
By the mid-1870s, Americans William Wallace, Charles Brush, and other inventors had made small-scale arc light demonstrations. The first large-scale application occurred in March 1878 when Jablochkoff arc lamps, powered by Gramme generators, lit the streets of Paris.
These intense arc lamps were not practical for use in small locations such as the home. After visiting Wallace’s factory, Edison proposed to make an incandescent lamp that was not as intense, required less power, and, unlike arc lamps, could be operated with multiple lamps in a circuit.
On December 21, 1879, Thomas Edison announced that he had achieved his goal. He produced several of the new “incandescent” lamps, and invited the public to visit his Menlo Park laboratory on New Year’s Eve to see them.
The response was immediate. Several scientists proclaimed Edison’s invention to be a fake. Gas stocks plummeted, and the stock of the Edison Electric Light Company soared to $3500 per share!
The demonstration consisted of about 60 lamps mounted on poles lighting the laboratory grounds and country roads in the neighborhood. Other lamps were installed in nearby houses. So many people came to see the demonstration that the Pennsylvania Railroad had to run special trains to accommodate them.
Today, only three of these first incandescent lamps are known. One of them is on display in the “Electricity Sparks Invention” gallery of the Museum.
Photo: FIRST PRACTICAL INCANDESCENT ELECTRIC LAMP. Unsigned, but by Thomas Edison. (Edison’s earliest lamps feature the sunburst paper label.) Round seal stem “pantaloon” press with long platinum press leads twisted & soldered to outer leads. Screw clamps connect inner leads to filament, made of carbonized Bristol board. Measures 9-1/4” in total length (including hook), 2-1/4” dia. globe, 1” dia. at neck. American, 1879