The black Jacob is 48 - 56s quality with a staple length of 7 - 10cm.
By coincidence one of the first recorded flock of Jacobs was in the mid 1700's was in Wentworth at the big house. Two flocks are recorded here and at Tarporley. They were introduced as a decorative parkland flock by the Fitzwilliam family at Wentworth Woodhouse. We don't have them anymore their place has been taken by a herd of dear.