In a large mixer bowl beat egg whites, cream of tartar, vanilla, and salt at medium speed until soft peaks form.
Gradually add granulated sugar, about 2 Tbsp at a time. Continue beating until stiff peaks form.
Sift about 1/4 of the flour mixture over white, and fold in lightly by hand. If bowl is too full, transfer to larger bowl.
Fold in remaining flour mixture by fourths. Turn into an ungreased 10-inch tube pan.
Bake at 350ºF on lowest rack for 40 minutes or until cake tests done. Invert cake in pan and cool completely. Loosen cake from pan before removing.