'The New Head Master', 1868. The Conservative Prime Minister, Lord Derby, resigned from office at the end of February 1868 due to failing health. The mantle, or in this case the birch, of power was handed over to the Chancellor of the Exchequer, Benjamin Disraeli. Wearing the cap and gown of the Principal, Disraeli is pleased to accept the challenge. From Punch, or the London Charivari, March 7, 1868.