A supporter of the Odiham Society, he met Charles Benoît Vial de Sainbel who was in England for the second time to try to set up a veterinary school, such as existed at Lyon; and whose profile was raised when he was asked to dissect the famous racehorse Eclipse.

Penn ran a successful campaign over a few years to implement his own version of Sainbel's original scheme.

[5] Penn, fluent in French, Greek, Latin and Hebrew, was a Fellow of the Society of Antiquaries and wrote several books dealing with Biblical criticism and published a number of competent translations of ancient Greek works, including a critical revision of the English version of the New Testament.

He also wrote some theological works particularly related to Biblical chronology (past and future) and the early history of post-Flood mankind.

[2] His major work as a scriptural geologist[6] was A Comparative Estimate of the Mineral and Mosaical Geologies, published in 1822.