Beat egg whites and salt until foamy. Add cream of tartar and beat until stiff but not dry. Fold in vanilla and small amount of sugar at a time. Sift small amount of flour at a time over mixture and blend lightly. Bake in ungreased 10-inch tube pan in slow oven (325 F.) about 1 hour. Invert on rack and cool about 1 hour before removing. Frost with Fluffy Frosting (see below) and arrange candles in holders on top of cake.