Cream butter; gradually add sugar, beating well. Add eggs, one at a time, beating well after each addition.
Combine the flour, cream of tartar, and salt; add to creamed mixture, mixing well. Stir in the brandy.
Pour batter into 2 well greased 9- x 5- x 3-inch loaf pans. Bake at 325° for 1 hour and 10 minutes or until a wooden pick inserted in center comes out clean. Cool in pans 10 minutes; remove from pans, and let cool completely.