CREATE TABLE table_18530 ("District" TEXT, "Incumbent" TEXT, "Party" TEXT, "First elected" FLOAT, "Result" TEXT, "Candidates" TEXT)

What year was incumbent barratt o'hara first elected?
SELECT "First elected" FROM table_18530 WHERE "Incumbent" = 'Barratt O''Hara'
SELECT "First elected" FROM "table_18530" WHERE "Incumbent" = 'Barratt O\'Hara'