In large bowl, combine flour, soda, salt and cream of tartar. Set aside. In mixing bowl, cream sugar, butter, eggs, lemon juice and rind until smooth. Stir in flour mixture. Chill dough 1 hour. Shape dough into 1-inch balls, roll in sugar. Place on greased cookie sheets, bake at 325 for about 15 minutes, until light golden brown. Cookies will be soft in center. Cool 2 minutes before removing to counter. Cool completely before storing.