The horizontal one prevents the main one to roll up in the narrow space between trees and the rear wall of the house, it whirls round upper in the center of the enclosure whose dimensions are fiit for break any gust.
It's an amazing winter experience to walk with difficulties on the cliff's way and once the green wall crossed you suddenly feel silent with not any blow.
On summer you feel very home inside this intimate greenness.
This kind of Norman enclosure is called "clos masure", for southern British: "cottages enclosure".
"Clos masure" are disappearing because it was a peasantry way of life where relationship was close from those in cod fishing. Miserable people hardly earned barely enough to eat. We always consider the peripheral mounds with deep respect, thinking it was put up by poor people who like thatchers were authorized to make green vegetables on mounds slops during their whole (short) life, it's why earth has a so hight quality, like a powder between fingers, maintained during centuries of hard ecology.