Stir together flour, baking powder, sugar, cream of tartarand salt. Cut in shortening unti mix resembles coarse crumbs.Make a well in the center. Add milk all at once. Stir together.Knead gently for 10-12 strokes. Knead gently for 1/2 inch thickness. Cut into 2 1/2 '' squares. Transfer to ungreasedbaking sheet. Bake in a 450o F oven for 10-12 minutes. Makes10-12 biscuits.