Beat egg whites slightly. Add cream of tartar and salt. Beat until very stiff. Add sugar slowly. Continue beating until sugar is dissolved. Grease an 8x12 pyrex cake pan. (Must be pryrex to hold heat). Heat oven to 450 F. Put in mixture and turn oven off. Let set in oven over night (do not peek). The next day whip cream and spread over the top. Refregerate at least 4 hours. Cut in squares and top with frozen strawberries or raspberries.