The first attempt to use steam power for oyster dredging of which we have any knowledge was made at Norwalk Conn when a boiler and engine were put on board the sloop Early Bird in 1874 for the purpose only of turning the drums with which the dredge lines were hauled. Later this vessel was further improved by the addition of a propeller and this was found to add so materially to her effectiveness that since that time several screw steamers have been built expressly for this work. They are generally of small size ranging from 20 to 53 tons from 50 to 83 feet in length with a beam of 12 to 20 feet.