TYRONE POWER CENTENNIAL: Film historian Philip Harwood presents the first of three lectures on the dashing actor. A screening of Rouben Mamoulian’s swashbuckler The Mark of Zorro (1940-94 min.), in which Don Diego Vega, disguised as the masked avenger, saves Los Angeles from despots and woos his enemy’s niece (Linda Darnell). 7:30 p.m.