James 's son Anthony succeeded in the titles on his father 's death in 1787 .
Their eldest son , James , succeeded his mother as 4th Earl of Newburgh and his father as titular 6th Earl of Derwentwater .
James 's son Anthony succeeded in the titles on son 's father 's death in 1787 .
Their eldest son , James , succeeded his mother as 4th Earl of Newburgh and his father as titular 6th Earl of Derwentwater .