Conversation so far:
What was the disaster for William Thomson, 1st Baron Kelvin?
Thomson sailed on the cable-laying expedition of the SS Great Eastern but cable was lost after 1,200 miles (1,900 km) had been laid and the project was abandoned.

Question: In what year did this happen?
Self-contained rewrite: In what year did the calbe-laying expedition of the SS Great Eastern with William Thomson, 1st Baron Kelvin being abandoned happen?