Heat oven to 375 degrees. Use a 10 x 4 inch ungreased tube pan. Sift flour and first amount of sugar together to blend. Measure egg whites, cream of tartar, and salt into large mixing bowl. Beat until foamy. Gradually add second amount of sugar. Continue beating until meringue holds stiff peaks. Fold in gently, only until the flour- sugar mixture disappears. Push batter into tube pan. Gently cut through batter. Bake 30 to 35 minutes. Invert on funnel. Let hang until cold.