Sift together flour and 1/2 cup sugar together 4 times.
Combine egg whites, salt, cream of tartar, vanilla, and almond extract in very large bowl. Beat until moist stiff peaks form.
Add 1 1/3 cups sugar in 4 additions, beating just until blended each time.
Fold in flour mixture in 4 additions, using a large wire whisk.
Pour into ungreased 10" tube pan. Cut through with knife to dislodge bubbles.
Bake at 375 for 35-40 minutes.
Cool upside down. Balance on a bottle if needed to clear top of cake from table.