Lemon Meringue Pie

Beat yolks of the eggs until a thick lemon color. Gradually add the sugar, 1 tablespoon at a time, beating constantly. Add the lemon juice and rind. Be sure there is no white on the inside of the rind. It is very bitter. Cook in the top of a double boiler over boiling water for 20 minutes, stirring constantly. Add a pinch of salt. The mixture should be quite thick at the end of 20 minutes. Remove from the heat. Beat the egg whites until very stiff and dry. Add the hot mixture a little at a time, stirring constantly. Pour into baked pie crust and place under broiler to brown. Cool at room temperature.