Born in New York City, New York, Bownes graduated from Columbia College with a Bachelor of Arts degree in 1941,[2] and after serving in the United States Marine Corps during World War II, graduated from Columbia Law School with a Bachelor of Laws in 1948.

In 1966, he was selected as a member of the Superior Court of New Hampshire, on which he served for two years.

[4] Bownes was nominated by President Lyndon B. Johnson on July 17, 1968, to a seat on the United States District Court for the District of New Hampshire vacated by Judge Aloysius Joseph Connor.

[3] Bownes was nominated by President Jimmy Carter on September 19, 1977, to a seat on the United States Court of Appeals for the First Circuit vacated by Judge Edward McEntee.

His service terminated on November 5, 2003, due to his death from pneumonia in New Haven, Connecticut.