Conversation so far:
Who was Oxford's first slade professor of fine art?
John Ruskin
When was John Ruskin appointed as slade professor?
1869
What happened after John Ruskin appointment as slade professor?
He delivered his inaugural lecture on his 51st birthday in 1870.

Question: What did he do after the inaugural lecture?
Self-contained rewrite: What did John Ruskin do after the inaugural lecture as slade professor?