Horse collar of the Oseberg ship burial). The problem with a breastcollar harness was that the actual shafts of the cart, chariot, or other vehicle are attached to a surcingle around the barrel of the horse. The breastplate primarily kept the surcingle from slipping back, not as the primary pushing object. This results in the horse literally pulling the load, a less efficient use of the animal. The modern breastcollar has traces which transfer the pull directly from the breastcollar, but a horse collar still is more effective for pulling heavy loads. After the breastcollar harness, the next and final evolutionary stage
Tree girth measurement trunks flare outward at their base. In some trees this flare or buttressing extends only a short distance up the trunk, while in others it may extend or more up the tree, but the measurement is still taken at this default height for consistency. If the flare at the base of the tree extends above this default girth height, then ideally a second girth measurement should be collected where possible above the basal flare and this height noted. Tree girth is one of the parameters commonly measured as part of various champion tree programs and documentation efforts. Other commonly used