Place the popover pan in the oven to heat. When hot start to mix the batter. Place in a measuring cup one egg, then fill with milk. Pour into a mixing bowl and then add One cup of sifted flour, One teaspoon of sugar, One-half teaspoon of salt. Beat with egg-beater until the mixture is a mass of bubbles on top, when the egg-beater is removed. This usually takes about five minutes. Now grease the hot popover pan well and fill one-half full with the batter. Place in a hot oven and bake for thirty-five minutes. Do not open the oven door for ten minutes after you put the popovers in. Opening the door before this period of time elapses prevents the mixture from springing or popping. After twenty minutes turn down the heat to moderate oven to prevent burning and to dry out the centers.