CREATE TABLE table_2238 ("No" FLOAT, "Season" FLOAT, "Ep" FLOAT, "Title" TEXT, "Writer" TEXT, "Director" TEXT, "Original airdate" TEXT, "Archive" TEXT)

Name the number of writers for airdate of 15 july 1967
SELECT COUNT("Writer") FROM table_2238 WHERE "Original airdate" = '15 July 1967'
SELECT COUNT("Writer") FROM "table_2238" WHERE "Original airdate" = '15 July 1967'