Complex sentence: After Farmer and Brindley, Hitch was employed by the sculptor Thomas Nicholls one of whose projects was work at Lord Bute's Cardiff Castle for the architect William Burges.
Split into simpler sentences: After Farmer and Brindley, Hitch was employed by sculptor Thomas Nicholls. One of Nicholl's projects was work at Lord Bute's Cardiff Castle for architect William Burges.