1. Wash and trim the artichokes and drop into a large pot of boiling, salted water. Add the lemon juice and cook, uncovered, at a gentle bubble for 30 to 40 minutes or until the stem ends are tender when pierced. Lift out with a slotted spoon and drain on absorbent paper.

2. Cut the artichokes into quarters lengthwise and remove the fuzzy chokes with a metal spoon. Cut each quarter in two, again lengthwise.

3. In a large bowl, combine the flour, baking powder, and salt. Whisk to blend thoroughly. Beat the water and egg whites in another bowl until frothy, then add to the dry ingredients. Add the club soda and stir to blend. Dip the pieces of artichoke into the batter and fry, a few at a time, in deep fat heated to 375°. Drain on absorbent paper and serve immediately with wedges of lemon.