Complex sentence: He became senior bursar of his college in 1825, and during a long tenure of the office only resigning it on his finally quitting Cambridge in 1837 his sound judgment and practical knowledge of business proved of great service.
Split into simpler sentences: He became senior bursar of his college in 1825, and during a long tenure of the office only resigning it when he left Cambridge in 1837. His sound judgment and practical knowledge of business proved of great service.