Conversation so far:
When did William Thomson, 1st Baron Kelvin attend CAmbridge?
in 1841, installed him, with extensive letters of introduction and ample accommodation, at Peterhouse, Cambridge.
What did he study there?
The study of mathematics, physics, and in particular, of electricity, had captivated his imagination.
Did he belong to any clubs?
While at Cambridge, Thomson was active in sports, athletics and sculling, winning the Colquhoun Sculls in 1843.
Did he have any other interests?
He was elected a fellow of St.
Peter's (as Peterhouse was often called at the time) in June 1845.

Question: What did he do as a fellow?
Self-contained rewrite: What did William Thomson do as a fellow?