Put the water in a saucepan; when it boils add the butter; when the butter is melted add the flour and beat it with a fork or wire whip until it is smooth and leaves the sides of the pan. Remove from the fire and add the eggs, one at a time, beating vigorously each one before adding the next. Let it stand until cold. When ready to serve, drop a spoonful at a time into moderately hot fat and fry for about 15 minutes. Take out on a skimmer and dry on brown paper. The batter will puff into hollow balls. If the fat is very hot it will crisp the outside too soon and prevent the balls from puffing. Fry only a few at a time, as they must be kept separated. Sprinkle with powdered sugar and pile on a folded napkin. Serve with lemon sauce made as follows.
Strain the juice of the lemons; add the powdered sugar, then the boiling water.