London scones

Sift three cupfuls of self-raising flour with two tablespoonfuls of castor sugar and a quarter of a teaspoonful of salt. Rub in 2oz. of butter, add the white of one egg without beating it, and mix with about half a pint of milk. Knead till smooth, make into five balls; roll each into a round half an inch thick. Cut each round into four scones and glaze with beaten yolk of egg. Bake for about 15 minutes.