[2][3] A right-handed batsman and bowler Penn played 18 times for Kent between 1870 and 1878 as well as appearing for MCC in 1874 and Gentlemen of the South between 1871 and 1874.
[1] His younger brothers Frank and Dick Penn also played for Kent and his son Eric Penn played for Cambridge University and MCC.
[4] William Penn became a member of the Institution of Mechanical Engineers in 1873, proposed by his father and Joseph Whitworth.
[5] He became a partner in the family business around the same time, began to manage the firm in 1875,[6] and in 1889, when the firm was incorporated as John Penn and Sons Ltd, he and his elder brother John were the two principal shareholders.
[8] Penn died at Belgravia in London in August 1921 aged 71.