Add the salt and baking-powder to the flour and sift them. Rub in the butter well. With a fork stir in lightly and quickly sufficient milk to make a soft dough. The dough must be only just stiff enough to roll. Flour the board well, turn the dough onto it, and lightly roll it to a half inch thickness. Cut it into small circles, brush the tops with milk, and bake in a quick oven for twenty to thirty minutes.