He married Helen Anne Mackenzie (1799-1866), daughter of
Lord Seaforth. Her sister,
Mary Elizabeth Frederica Mackenzie, was the wife of Vice Admiral
Sir Samuel Hood and
James Alexander Stewart of
Glasserton. Together, Joshua and Helen were the parents of several children, including: In 1825, he was living at 6 Royal Circus in
Edinburgh's Second New Town. In later life, he moved to Belmont House, a substantial mansion west of the city, near
Corstorphine. He died on 17 November 1851. He is buried with his parents in
Greyfriars Kirkyard. The grave lies against the retaining wall mid-way along the northern slope. ==References==