user: Question: When was the Stokers' training ship launched?
Columns: ['Ship', 'Laid down', 'Builder', 'Engine-builder', 'Launched', 'Completed', 'Disposition', 'Fate']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Comus', '17 August 1876', 'John Elder', 'John Elder', '3 April 1878', '23 October 1879', 'Struck 1902', 'Sold for breaking 1904']
SQL:

assistant: SELECT "Launched" FROM "Table" WHERE "Disposition" = 'Stokers'' training ship';