When did the episode "rowley 1898" air?
CREATE TABLE "table1_25390694_2" (
  "series_num" real,
  "title" text,
  "director" text,
  "writer" text,
  "air_date" text,
  "production_code" real
);
SELECT "air_date" FROM "table1_25390694_2" WHERE "title"='\"Rowley 1898\"';