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 known to approximate the measurements: 1) distance of the camera from the tree, 2) distance from the camera to the scale, and 3) size of the object to be used as a scale. An Excel spreadsheet can be used to determine the rate the apparent size of the scale changes with distance, and that value can be used to calculate the diameter of the tree given that the tree is circular in cross section and the distance to the front side of the tree is known. Girth then is calculated by multiplying the diameter by pi. The method may be