In a bowl beat egg whites with cream of tartar and salt until they hold soft peaks.
Continue beating and gradually add sugar, one tablespoonful at a time until mixture holds stiff peaks.
Fold in vanilla.
Butter a cookie sheet; cover cookie sheet with buttered wax paper.
Drop meringue on paper in 4 equal mounds and smooth each mound into 1/2 inch thickness.
Bake at 270Â°F for 50 minutes; until completely dry.
Remove paper from cookie sheet; meringues from paper; cool on a rack.