CREATE TABLE "timeline_of_tallest_skyscrapers" (
  "name" text,
  "city" text,
  "height_feet_m" text,
  "year" real,
  "period" text,
  "surpassed_by" text
);

Question: What was the period for 1896?
SQL: SELECT "period" FROM "timeline_of_tallest_skyscrapers" WHERE "year"=1896;

Question: Tell me the height which has a surpassed by of book tower
SQL: SELECT "height_feet_m" FROM "timeline_of_tallest_skyscrapers" WHERE "surpassed_by"='book tower';

Question: I need the surpassed for years before 1925 and period of 6 years
SQL: SELECT "surpassed_by" FROM "timeline_of_tallest_skyscrapers" WHERE "year"<1925 AND "period"='6 years';