From the Register of Deaths at Sea :
Ship - Cordelia, Official No. - 26981, Missing since 21-9-1878, Robt Wilson, Sex Male, Age - 54, Rank - Master, Born - Seaton Sluice, Last Abode - 8 Russel St., N. Shields, Cause of death - supposed drowned.
Another 14 crew listed, four from Finland, three Germans, two Swedes, youngest a boy aged 13.
Can't see a suitable John Farrell in the Register, so probably didn't die at sea.
Alan.