Francis Blake Jr. (December 25, 1850 – January 20, 1913) was an American inventor.

Biography

Francis Blake was born in

Needham, Massachusetts Needham ( ) is a town in Norfolk County, Massachusetts. A suburb of Boston, its population was 32,091 at the 2020 U.S. Census. It is home of Olin College. History Early settlement Needham was first settled in 1680 with the purchase of a ...

on December 25, 1850, the son of Caroline Burling (Trumbull) and Francis Blake, Sr. In 1879, he invented a

carbon microphone The carbon microphone, also known as carbon button microphone, button microphone, or carbon transmitter, is a type of microphone, a transducer that converts sound to an electrical audio signal. It consists of two metal plates separated by granu ...

for use in the telephone, and patented it shortly after

Thomas Edison Thomas Alva Edison (February 11, 1847October 18, 1931) was an American inventor and businessman. He developed many devices in fields such as electric power generation, mass communication, sound recording, and motion pictures. These inventio ...

invented a similar microphone that also used carbon contacts. Blake used a carbon button design that initially would not stay in adjustment, but with later improvements proved to be workable.

Alexander Graham Bell Alexander Graham Bell (, born Alexander Bell; March 3, 1847 – August 2, 1922) was a Scottish-born inventor, scientist and engineer who is credited with patenting the first practical telephone. He also co-founded the American Telephone and Te ...

hired Blake and put him to work with

Emile Berliner Emile Berliner (May 20, 1851 – August 3, 1929) originally Emil Berliner, was a German-American inventor. He is best known for inventing the lateral-cut flat disc record (called a "gramophone record" in British and American English) used with a ...

who also invented a carbon microphone. The improved Berliner-Blake microphone was standard with the Bell company for many years. Blake also improved the construction of the

microtome A microtome (from the Greek ''mikros'', meaning "small", and ''temnein'', meaning "to cut") is a cutting tool used to produce extremely thin slices of material known as ''sections''. Important in science, microtomes are used in microscopy, allow ...

and

photographic shutter In photography, a shutter is a device that allows light to pass for a determined period, exposing photographic film or a photosensitive digital sensor to light in order to capture a permanent image of a scene. A shutter can also be used to allow ...

. Blake worked on the

United States Coast Survey United may refer to: Places * United, Pennsylvania, an unincorporated community * United, West Virginia, an unincorporated community Arts and entertainment Films * ''United'' (2003 film), a Norwegian film * ''United'' (2011 film), a BBC Two fi ...

from his teenage years through early adulthood (1866-1878). He was a physicist and an amateur photographer. In 1874, Blake married Elizabeth Livermore Hubbard (1849-1941) whose father provided land in Weston, on which Blake designed and built an elaborate house where he conducted his electrical experiments. They had two children: Agnes (Blake) Fitzgerald (b. 1876) and Benjamin Sewall Blake (b. 1877). Blake was elected a member of the

American Antiquarian Society The American Antiquarian Society (AAS), located in Worcester, Massachusetts, is both a learned society and a national research library of pre-twentieth-century American history and culture. Founded in 1812, it is the oldest historical society in ...

in 1900. He died at his home in Boston on January 20, 1913.

Patents

* Canadian patent 10021 for telephone transmitter, granted May 28, 1879, voided March 3, 1887 because of failure to manufacture telephone parts in Canada. * US patent granted in 1881

References

* Lewis Coe, ''The Telephone and its Several Inventors'', McFarland Publishers, 1995. * Elton W. Hall, ''Francis Blake: An Inventor's Life'', Massachusetts Historical Society, 2004

External links

Blake Transmitters

* ttps://web.archive.org/web/20080515072006/http://www.techantiques.com/blake_home_page.htm Blake website {{DEFAULTSORT:Blake, Francis Engineers from Massachusetts American inventors Members of the American Antiquarian Society People from Needham, Massachusetts 1850 births 1913 deaths