Frank E. Mason (1853-1906) was born in Cambridge, Massachusetts, and died in Saint Remy, New York. He married Harriet E. Mason (b. Sands) in Providence, Rhode Island, in 1877. He followed in his father's profession of civil engineering for a number of years before becoming a student of Mary Baker Eddy's and completing the Primary class in May 1887, the Normal class in October 1887, and the Obstetrics class in October 1888. He became a member of the Christian Scientist Association in June 1887, and he was a member of the National Christian Scientist Association as well as the Christian Science Mission and Dispensary Association. After living there for almost four years, Eddy sublet 571 Columbus Avenue (also the home of the Massachusetts Metaphysical College) to Mason in January 1888. That same year, Mason was made assistant pastor of the Church of Christ, Scientist, Boston. As Eddy's assistant pastor, Mason preached at services when Eddy could not be there and also came up with lessons of his own. An announcement in the June 1888 issue of The Christian Science Journal (of which Mason was a frequent contributor) explained that the new lessons would be "notes on the International Sunday-school Lessons." International Sunday School lessons were popular public study guides to Bible texts that Mason would use as the basis for Christian Science lessons. Like Eddy's lessons, Mason's notes were sermon-like commentaries. He probed the symbolism and spiritual meanings of Bible narratives, and generally included specific references to Science and Health with Key to the Scriptures. Mason served as manager of The Christian Science Publishing Society from August 1888 to June 1889. In 1888, The Christian Science Publishing Society published his Birdseye View of Christian Science: An Address Given at the National Christian Scientist Association Chicago June 14, 1888. When Eddy resigned the pastorate of the church in May of 1889, Mason's resignation as assistant pastor was also accepted. Mason became pastor of First Church of Christ, Scientist, Brooklyn, New York, in October 1889 for a short time before leaving Christian Science. He organized the Francis E. Mason Publishing Company and carried on his own version of Christian Science ideas in a magazine called The Seed (later known as The Rostrum, followed by The Healer, and Dominion) and published articles aimed at discrediting Eddy. Mason became pastor of his Church of the Independent Dominion in Brooklyn and is associated with the New Thought movement. He was president of the Brooklyn Public Health Society.

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