Bronc riding toward the rigging handle, spurring at each jump in rhythm with the motion of the horse. Bareback bronc riding began to develop as a professional rodeo sporting event around 1900. The riding equipment used during that era varied. In some cases, the rider simply held onto the horse's mane, called a mane-hold. Others held a loose or twisted rope tied around the horse's girth, and other methods involved using multiple handhold leather riggings based on a surcingle. In the early 1920s, when the old rodeo rules allowing two handed riding were being phased out and replaced with the newer rule
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