I assume that you might be referring to the
Horse Powered Ferry Boat. Click on "See Details" below the drawing of the Horse Powered Ferry boat for more
visual details. There are gears and a shaft from the large merry-go-round like wheel that exists below the deck that drives the shaft with the paddle wheels. A lever with gears in the middle of this shaft can change the gears so that the boat can go forward or backward. A tiller is used to turn the boat. Hope this helps.