Over the last two weeks—December 23, 2017 to January 7, 2018—during our random walks in the arroyos and ranchlands around Alamos, we have encountered two gate-closers we have never seen in our almost twenty years of rambling in southernmost Sonora. The design is almost identical to the metal gate-closers that are common and characteristic of the Sandhills of Nebraska.
Between us, David and I have opened and closed Sonoran gates a few hundred times if not more. Most of them are simple stretch gates—barbed wire strung between a series of slender poles fashioned from one of the native trees. This floppy gate is secured by means of a wire loop that attaches to the gatepost, also of local wood. These gates vary in temperament. Some are easy to close and others almost impossible. The person provides the lever force, and for the harder-to-close stretch gates this can lead to pinched fingers and bloody barbed wire pokes, at least in my experience.
“The lever is a simple machine that changes the magnitude and direction of the force applied to move an object. It minimizes the effort required to lift the object. A lever
is a rigid bar which moves around a supporting point (pivot or fulcrum).”
The mechanical principle and virtue of the Sandhills—now apparently Sonoran—gate-closer is that it is the lever, thereby reducing the potential injury and embarrassment of the person who cannot close a difficult stretch gate.
The lever gate-closer, whether of metal or wood, is an elegant machine and lovely to behold. And added to the beauty is the mystery. Will we encounter more of these gate-closers in Sonora? How did the two we have seen come to be here? Did an ingenious Sonoran rancher or ranch hand simply apply the physics of leverage to make a better gate-closer? Or did a Sonoran spend some time on a ranch in the Sandhills and bring this technology back to his native landscape in Sonora?