Ronald George Grumble was an instrument maker and inventor. He was born in Watford, Hertfordshire, in the summer of 1902, the fourth of seven children, Isabella, Annie Rose, John, Ronald, Frank, who died as a baby, Arthur and Leonard. His father George was a house painter.
Ronald and his sister Annie Rose lived with their parents at 18 Lovelace Green, Eltham, Kent, throughout their lives. Neither married. Their mother died in 1941, and their father in 1957. Meanwhile, their brother Arthur got married in 1934 to Daisy Rose Manthey (also known as Higgs on her mother’s remarriage). and Arthur and Daisy moved to Lee High Road with their brother Leonard.
Ron’s tea maker, invented in 1930, was known as the Early Morning Waiter. I believe it was Daisy who later donated Ron’s Early Morning Waiter to the Science Museum.