CREATE TABLE table_18282 ("District" CLOB, "Incumbent" CLOB, "Party" CLOB, "First elected" FLOAT, "Result" CLOB, "Candidates" CLOB)

In which district is Robert W. Edgar the incumbent?
SELECT "District" FROM table_18282 WHERE "Incumbent" = 'Robert W. Edgar'
SELECT "District" FROM "table_18282" WHERE "Incumbent" = 'Robert W. Edgar'