Beat 4 egg whites with cream of tartar, gradually add 1 cup sugar after soft peaks have formed... Beat until stiff, but not dry. Spread on bottom and sides of buttered 9 inch pie pan. Bake at 350 degrees for 45-60 minutes. If crust is getting too brown you can put strip of foil around... Cool. Take 4 egg yolks and beat slightly. Stir in 1/2 cup sugar, 3 Tbsp. lemon juice and 1 Tbsp. grated lemon rind, 1/4 tsp. salt. Cook until thickened in microwave for 4 minutes (stir every 30 seconds) Cool. Whip 2 cups whipping cream and fold 1/2 of whip cream into lemon mixture. Pour into cooled meringue shell. Top with the remaining whip cream. Chill for 24 hours.