PREHEAT oven to 225°F. Beat egg whites and cream of tartar in small bowl with electric mixer on high speed 5 minutes or until soft peaks form. Gradually add sugar, 1 Tbsp. at a time, beating on high speed until stiff peaks form.
DROP tablespoonfuls of the egg white mixture onto baking sheet covered with parchment paper. Sprinkle each meringue lightly with dry gelatin powders.
BAKE 50 minutes. Turn oven off. Prop oven door open slightly; let meringues stand in oven for 1 hour or until completely cooled.