Question: In what Year is the Gauge 2 ft 6 in?
SQL: SELECT "Year" FROM "2-15194650-1" WHERE "Gauge" = '2 ft 6 in';

Question: In what Year is the Works No. 2040-2049?
SQL: SELECT "Year" FROM "2-15194650-1" WHERE "Works no." = '2040-2049';

Question: What is the Gauge of Builder Beyer, Peacock?
SQL: SELECT "Gauge" FROM "2-15194650-1" WHERE "Builder" = 'Beyer, Peacock';