Tart lemon frosting

MMMMM----- Recipe via Meal-Master (tm) v8.02
  
       Title: TART LEMON FROSTING
  Categories: Cakes, Frostings
       Yield: 1 servings
  
       1 ts Lemon rind; grated
       4 tb Butter
       3 c  Conf. sugar; sifted
       3 tb Lemon juice
       1 ds Salt
  
   Add lemon rind to butter; cream well. Add part of sugar gradually,
   blending after each  addition.  Add remaining sugar, altemately with
   lemon juice, until of right consistency to spread. Beat thoroughly
   after each addition. Add salt. Makes enough frosting to cover the top
   of one layer and sides of three 9-inch layers.
  
 MMMMM