In 1891 Henry Davis Trounce, aged 10, born in Menheniot Cornwall, scholar, was at Christchurch Newgate Street, London, England.
In 1930 Harry D. Trounce, aged 44, born in England, structural engineer, wife Helen M Trounce, aged 38, born in Ohio USA, and daughters (born in California) Kathleen M Trounce (8) and Maureen C. (2½), were with Helen's mother Mary E Mannix, widow, in San Diego Township, San Diego, California, USA.
In 1940 Harry D Trounce, aged 53, born in England, salesman, and wife Helen N Trounce, aged 38, born in Ohio, and daughters Kathleen M and Maureen, were with Helen's sister Elizabeth Mannix in San Diego Township, San Diego, California.
Harry's age is understated in the US censuses.