In a large bowl, cream the butter, shortening and 1-1/2 cups sugar until light and fluffy. Beat in eggs and extract. Combine the flour, cream of tartar, baking soda and salt; gradually add to creamed mixture and mix well. , In a shallow bowl, combine the nutmeg and remaining sugar. Roll dough into 1-in. balls; roll in sugar mixture. Place 2 in. apart on ungreased baking sheets. , Bake at 400° for 10-12 minutes or until lightly browned. Remove to wire racks to cool.