CHOCOLATE PIE CRUST: Sift the salt and flour into a bowl and cut in the shortening, using a pastry blender, until coarse crumbs form. Add the chocolate and water, tossing with a fork, until the dough forms. Press the dough firmly into a ball and then roll out on a lightly floured surface into a 13-inch circle. Loosely fit the dough into a 9-inch pie plate and trim the edge so that there it reaches 1 inch beyond the rim of the pie plate. Fold the extra under the edge of the crust to from a ridge. Flute the edge and prick the entire surface of the pie shell with a fork. Bake at 400 degrees F for 12 minutes or until a golden brown. Cool on a rack. CHOCOLATE PIE: Stir the 1/4 cup of sugar, the gelatin and salt together in a 2-quart saucepan. Stir in the milk and slightly beaten egg yolks. Add 3 (1 oz) squares of unsweetened chocolate and cook over low heat, stirring constantly, until the chocolate melts and the gelatin dissolves. Remove from the heat and stir in the vanilla. Chill in the refrigerator, stirring occasionally, until the mixture is the consistency of unbeaten egg whites. Remove the chocolate mixture from the refrigerator and set aside Immediately beat the egg whites and cream of tartar, in another bowl, until foamy, using an electric mixer set on high speed. Gradually add the 1/4 cup of sugar, 1 Tbls at a time, beating well after each addition. Continue beating until stiff, glossy peaks form when the beaters are slowly lifted. When the chocolate mixture mounds slightly when dropped from a spoon, beat until smooth, using an electric mixer at medium speed. Fold the egg white mixture into the chocolate mixture; then fold in the whipped cream. Chill in the refrigerator until the mixture mounds well when spooned. Turn into the chocolate pie shell. Chill in the refrigerator for 2 hours or until set. To serve, decorate the pie with puffs of sweetened whipped cream. Grate and sprinkle the chocolate over the whipped cream.