Francis Blake was born in Needham, Massachusetts on December 25, 1850, the son of Caroline Burling (Trumbull) and Francis Blake, Sr.[1] In 1879, he invented a carbon microphone for use in the telephone, and patented[2][3][4] it shortly after Thomas Edison 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 hired Blake and put him to work with Emile Berliner who also invented a carbon microphone.

The improved Berliner-Blake microphone was standard with the Bell company for many years.

[8] Blake worked on the United States Coast Survey from his teenage years through early adulthood (1866-1878).