CREATE TABLE table_66472 ("Rank:" FLOAT, "State:" TEXT, "Premier:" TEXT, "Party:" TEXT, "Assumed office:" TEXT, "Left office:" TEXT, "TOTAL Time in office:" TEXT)

Premier Sir Charles Cowper (1807-1875) KCMG left office 2 October 1856, when did he assume office?
SELECT "Assumed office:" FROM table_66472 WHERE "Premier:" = 'sir charles cowper (1807-1875) kcmg' AND "Left office:" = '2 october 1856'
SELECT "Assumed office:" FROM "table_66472" WHERE "Left office:" = '2 october 1856' AND "Premier:" = 'sir charles cowper (1807-1875) kcmg'