Weigh out a pound and a quarter of sifted flour, and a pound of butter. Rub about one-third of the butter with two-thirds of the flour, and a teaspoonful of salt. When the butter is thoroughly mixed with the flour, add one beaten egg, and cold water to moisten it sufficiently to roll out. Sprinkle part of the reserved flour on a board, cut the butter left into small pieces, and roll them out as thin as possible. Lay the butter, as fast as rolled out, on a floured plate, each piece by itself - roll out the pastry as thin as it can be rolled, cover it with the rolled butter, sprinkle on part of the reserved flour, and roll the crust up. Continue to roll out the crust, and put on the reserved butter and flour, till the whole is used. Roll it out lightly, about half an inch thick, for the upper crust, or rim to your pies - plain pie crust should be used for the under crust. Or, instead of flour, sprinkle some "baking powder" on each layer of butter; when the butter melts, it will cause the powder to effervesce and puff up the paste. To make the "baking powder," take one ounce of carbonate of soda, and seven drachms of Tartaric acid, mix well: it may be conveniently applied by means of a common pepper-pot kept for the purpose. Puff pastry, to be nice, should be baked in a quick oven till of a light brown color. If it browns before the fruit in the pie is sufficiently baked, cover it with thick paper.