Do not preheat the oven. Grease 10 inch tube pan and line bottom with wax paper or parchment paper.
Sift together the flour, baking powder and salt. Set aside.
In a large bowl, beat the butter, shortening, and sugar on low speed for 10 minutes. Add the eggs one at a time, blending well after each addition. Alternately add the flour mixture and milk, mixing well. Add the vanilla and lemon extracts.
Pour batter into the prepared pan. Set the oven temperature to 350 degrees F (175 degrees C. Bake for 1 hour and 20 minutes, or until a toothpick inserted into the middle of cake comes out clean. Allow cake to cool in the pan for 1 hour. Remove to a cake rack and cool for at least 3 hours.