Amos Dolbear

Biography

Amos Dolbear was born in 1837 in Connecticut and is well known for his invention of a system for transmitting telegraph signals without wires in 1882 among many other important inventions. He died in 1910.

He graduated Ohio Wesleyan University in Ohio in 1866 and became as assistant instructor in the Chemistry Department at the University of Michigan. He received an M.A. and a M.E. for Michigan. He then became an assistant professor of Natural History at Kentucky University. He then became a professor of Physics and Chemistry at Bethany College in 1868. In 1874 he accepted the chair of the Physics and Astronomy Department at Tufts College and continued his research there for the rest of his career.

While still a student he invented a receiver containing a permanent magnet and a metallic diaphragm. In 1865 he invented the first telephone receiver with a permanent magnet, 11 years before Bell's patent. Dolbear couldn't prove that he invented it first and lost his case before the U.S. Supreme Court.

Several developments followed his idea. In 1876 he patented a magneto electric telephone, followed by a static telephone in 1879. Then, in 1882, Dolbear created a telegraph that could communicate over a quarter of a mile without wires, using conduction in the ground. He received a patent for it in 1886.

He also invented the electric gyroscope to demonstrate Earth's rotation, the opeidoscope, and a new system of incandescent lighting. He was recognized for his contributions to science at the Paris Exposition in 1881 and the Crystal Palace Exposition in 1882. Dolbear was also a member of the American Association of Arts and Sciences, the American Association for the Advancement of Science and an examiner at the World's Fair.

Further Reading

http://waywiser.rc.fas.harvard.edu/people/841/amos-e-dolbear

https://patents.google.com/patent/US239742

https://web.archive.org/web/20140104231056/http://dl.tufts.edu/catalog/tei/tufts:UA069.005.DO.00001/chapter/D00047