Combine Flour, Sugar, Salt And Cocoa In A Large Bowl. Mix In A Sauce Pan, Water, Oil And Butter. Bring To A Boil. Pour Into Dry Mix And Beat Until Smooth. Add Buttermilk, Eggs And Soda. Beat; Batter Will Be Thin. Pour Into Well Greased Jeely Roll Pan. Cool On A Wire Rack; While Still A Little Warm, Frost With Rocky Road Frosting (See Recipe On Page Xx).