Thomas Mason senior mentions four of his sons in his will, including Frederick.

Frederick was probably the youngest son, born at Dedham in about 1805. He was thus around the same age as his nephew, the eldest son of his brother Thomas junior.

Frederick must have moved to Brightlingsea with his father in 1816 as by the 1830s he was working as a farmer and miller in or near the town. He was in business with a Henry Mason, until February 1834 when it was announced in the Essex Standard that the partnership was dissolved by mutual consent, with all debts due to be paid to Frederick , who was ‘empowered to give a discharge for the same’. It is not clear if Henry was a brother.

Frederick was still living at Brightlingsea when his daughters Louisa (1833) and Eliza Sarah (1836) were born. But the family must have moved to Dedham in the late 1830s as a son, Frederick, was baptised there in about 1840. The following year when the census was taken they were living on Ardleigh Road, Dedham.

In 1851 Frederick was widowed and living at Hill House, Great Bromley. His occupation, oddly, was given as Registrar of Births and Deaths. So perhaps he worked on the census taken that year? After this it looks like he took work as a gardener and in 1861 he had remarried and was living in Colchester. It looks like he died at Colchester in 1873, aged sixty-nine.