" We now offer to the most particular (wagon) builder a fifth-wheel with gear connections for drop center work which is ideal in every respect. ..has a connection for spring carrier to take the weight off the horse. Can be used on pole or shafts."
Internet: The term fifth wheel comes from a similar coupling used on four-wheel horse-drawn carriages and wagons. The device allowed the front axle assembly to pivot in the horizontal plane, to facilitate turning.
