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 Converting the girth measurement to a diameter will always overstate the cross-sectional area of the trunk, therefore it is best to record the raw girth numbers directly rather than convert them to diameters. The conversion of girth values to approximate diameters can always be done later if needed for other types of analysis. Measuring tree girth directly is a common educational technique allowing students to learn about their local environment in a practical manner. It is often used in the primary setting to introduce topics such as measuring, using numbers and simple calculation. Simple techniques can be used to estimate