John Hammond

Character is the real foundation of all worthwhile success.
John Hays Hammond

John Hays Hammond Jr. (1888–1965)
John Hays Hammond Jr. (1888–1965) in 1922

While studying at the Sheffield Scientific School of Yale University in 1907-1910, the young American John Hays Hammond Jr. (1888–1965) became interested in the new study of radio waves, and he was taken under the wing of Alexander Graham Bell, who not only became his mentor, but the two would remain close friends until Bell’s death in 1922. After graduating from Yale in 1910, Hammond took a job in the U.S. Patent Office, following the advice of his other mentor—Thomas Edison, who told him: “Inventing had to be a money-making proposition, where better to learn what fields were up-and-coming than in the Patent Office?” After he became an authority on the patent process, in 1911 Hammond founded the Hammond Radio Research Laboratory on his father’s estate in Gloucester, Massachusetts.

In the same 1911, Hammond hired as assistants two very good engineers—the young Indiana-born Benjamin Franklin Miessner (1890–1976), who just left the Navy, where he worked as a radio operator and invented the “cat whisker” detector which allowed for receiving radio waves by crystal sets, and Fritz Löwenstein (1874-1922). Lowenstein was an Austrian electrical engineer (Ashkenazi Jew, born in Ostrov Schlackenwerth, Bohemia, where his family owned a porcelain factory), who emigrated to the USA in 1899, and around 1900 worked as an assistant of the great inventor Nikola Tesla and accompanied him to Colorado Springs where they conducted a series of experiments with lightning and wireless transmission. Tesla described him as “a man possessed of the highest technical training.” Then Lowenstein worked for Lee de Forest, became a famous radio engineer, and built the first sound amplifier.

In 1912 Hammond started a project for the so-called Electric Dog, a mobile mechanism that would respond to light signals using selenium cells. The Electric Dog was a fun way to help people learn about science and was considered the ancestor of all self-directing robots of a phototropic nature. Miessner refined the design and ultimately built the device, with the help of Lowenstein. Later Miessner left Hammond’s employ, but Hammond allowed him to borrow and demonstrate the model.

The Electric Dog, Popular Science Monthly, March 1916
The Electric Dog, Popular Science Monthly, March 1916

Electric Dog worked with two cells of selenium behind each glass eye. When a light was flashed, and it fell on either eye, this reduced the electrical resistance of the selenium, allowing electrical currents to pass through. This started the motor which began turning the dog’s wheels. If neither selenium cell ‘eye’ received light sufficient to reduce its resistance so that its associated relay operated, then no power would reach the Motor and the Dog would remain OFF. If both ‘eyes’ received sufficient light then power would be supplied to the Motor but the solenoids would be OFF so the Dog would steer straight ahead.

If the light came through one eye; for example, the right eye, then the current would only pass through that particular eye. The way the electro-magnets and batteries were arranged would pull the rear wheel to the right. This would cause the dog to turn straight towards the light and the light would then shine into both eyes. The wheels would go straight again. Anytime the Electric Dog saw light, he would begin to move. To demonstrate how the Electric Dog worked Miessner put the device into action. From an electric flash, he threw light into the dog’s groggy eyes, and the machine began obediently moving toward his master. The dog would follow Miessner wherever he went with the light. The directional orientation of the dog corresponded to his light.

In May 1912 Hammond applied for a patent for the circuit of the “electric dog” (see US pat. Nr. 1387850 for System of Radiodirective Control).