1. Combine Lemon Juice, lemon rind, and sweetened condensed milk.
2. Add two egg yolks and stir until blended.
3. Pour into graham cracker crust.
4. In a chilled glass bowl, add two egg whites and cream of tartar. (Or double if you like extra high meringue)
5. Beat until almost stiff enough to hold a peak.
6. Gradually add sugar and continue beating until stiff but not dry.
7. Pile meringue on top of lemon filling sealing to edges. Use the back of the spoon to lightly create peaks.
8. Bake in a slow oven (325 F) until lightly browned, about 15 minutes. Cool.