the 1698 census of Hempstead. At the time there are David and Hannah Jaycocks, with William, Joseph and Francis (presumably couple and sons.) I would guess David to be a son of William Jaycocks. There is a Grace Jaycocks, whom I can't place, as the only Grace that I know of was born more than a 100 years before; maybe an unmarried granddaughter of Francis and Grace. But there is a Benjamin Jaycocks, either living alone or with either the preceding or following family (the census is assumed to be door-to-door.) There is some chance that this is a close relative of your Benjamin, and that your Benjamin was born in Hempstead, or the son of someone who was.