Never Fail Frosting

Directions

1. 1
   Place sugar, unbeaten egg whites, cream of tartar and water in top of double boiler.
2. 2
   With eggbeater, whip briskly while cooking mixture over vigorously boiling water, but do not touch top of upper pan.
3. 3
   Whip until stiffly beaten.
4. 4
   Remove from heat and add vanilla.