This improvement consists in part, in the arrangement of two sets of levers and hand poles on each side, in such a manner that "when force is applied to the hand-poles of the outside levers, in a reverse direction to that which is applied to the hand poles of the inside levers, both powers will agree in forcing the pistons of the pumps in one and the same direction, while the reverse motion of the levers will prevent the engine from rocking". Entered at the Patent Office, on the 10th instant, by Barton & Button.