user: Question: Who was the Builder for the locomotive that has a works number of 323?
Columns: ['Number', 'Name', 'Type', 'Builder', 'Works number', 'Date built']
Types: ['real', 'text', 'text', 'text', 'text', 'real']
Sample row: [1.0, 'Talyllyn', '0-4-2 ST', 'Fletcher,Jennings &Co. , Whitehaven', '42', 1864.0]
SQL:

assistant: SELECT "Builder" FROM "Table" WHERE "Works number" = '323';