Alexander Graham Bell’s work echoes here. Though the name “Watson” might conjure images of Sherlock Holmes’s companion, this Watson links to Bell’s world. Bell hired Thomas Watson’s namesake, Charles Sumner Tainter, as his lab assistant. This collaboration at 1325 L Street NW led to groundbreaking work.
Bell’s story in D.C. is one of innovation. In 1879, Bell established his first D.C. laboratory at 1325 L Street NW. Here he aimed to develop new telephone transmitters. He also wanted to pursue methods of recording sound. Measuring distance by sound was another goal. Tainter joined him for $15 per week. They began working on the photophone.
The photophone marked a significant achievement. It used a sensitive selenium crystal. A mirror vibrated in response to sound. This enabled sound to be transmitted on a beam of light. Bell envisioned it acting like an ordinary telephone.
Success came on February 19, 1880. Inside the L Street lab, they interrupted sunlight with a rotating disk. The light fell upon a selenium cell. A musical tone was then heard from a telephone receiver. The receiver was connected in series with the selenium and a battery.
To test it, Tainter stayed with the apparatus. Bell went to the lab basement with telephone receivers. On the first try, Bell clearly heard Tainter say “Hoy, hoy.” He also heard him sing Auld Lang Syne. They switched places and replicated the results. Bell was thrilled.
Bell wrote to his father on February 26, 1880. He exclaimed he had heard speech produced by sunlight. He described hearing a ray of the sun laugh, cough, and sing.
For months, Bell and Tainter worked secretly on L Street. Lawsuits over the telephone patent made Bell hesitant to announce prematurely. On April 1, 1880, they transmitted their voices 79.62 meters. The sound traveled down an alley on Massachusetts Avenue. It reached a back window of their lab. Bell noted they had succeeded in producing speech at a distance by light. He saw perfection of apparatus as the next step. He wanted to reproduce speech at thousands of meters away.
The Franklin School played a crucial role. On June 3, 1880, Tainter went to the school’s roof. He transmitted sound 213 meters to Bell at the L Street lab. It was the first instance of long-distance wireless communication. This preceded wireless radio voice communication by almost 20 years.
Bell later wrote about hearing the sentence. It said “Mr. Bell if you understand what I say come to the window and wave your hat.” He waved with vigor. He described it as a moment worth a lifetime.
The photophone’s centennial was celebrated on February 19, 1980. Representatives from National Geographic, the Smithsonian, and Bell Laboratories gathered. They paid tribute to Bell with a photophone demonstration. It took place on the Massachusetts Avenue alley. An exhibit at the National Geographic Society celebrated the photophone. The Smithsonian lent Bell’s original photophone for the exhibit.
Bell also invented a metal detector in D.C. He used it to locate the bullet that killed President Garfield. He was not able to accurately find the bullet. Metal coils in the President’s mattress interfered. The device did locate bullets in Civil War veterans.
Bell considered the photophone his greatest invention. He thought it was greater than the telephone. His Franklin School experiment had lasting effects. It reveals the principle upon which today’s laser and fiber optic systems are founded. Modern communication can be traced back to Bell’s D.C. labs.