saying that the mother was herself under a duty to maintain the child. I regard the father's promise in this case as what Is sometimes called a unilateral contract, a promise in return for an act, a promise by the father to pay &1 a week in of looking after the child, there was a binding contract. . So long as she looked after the child, she would be entitled to 1 a week. The case seems to me to be within the decision of Hicks & Gregory (reported in 8 Common Bench Reports at page 379) on which the judge relied. I would dismiss the appeal. The case illustrates the rather elaborate reasoning of the judges to 'construct consideration' yet maintain the status quo. Dening LJ returned to the theme that the promise to perform an existing duty can constitute a good consideration in Williams v Williams [1957] 1 WLR 148 See: Denning LJ in Ward v Byham "I have always thought that a promise to perform an existing duty, or the performance of it, should be regarded as good consideration, because it is a benefit to the person to whom it is given." Contrast this with the earlier cases on natural love and affection, White v Bluett et al. Performance of a duty owed under an existing contract The performance of an act already required under a prior contract cannot be a good consideration for a later promise. Stilk v Myrick (1809) 2 Camp 317 Sailors jumped ship.