ART. 3. A steam vessel when towing another vessel shall, in addition to her side lights, carry two bright white lights in a vertical line one over the other, not less than three feet apart, and when towing more than one vessel shall carry an additional bright white light three feet above or below such lights, if the length of the tow measuring from the stern of the towing vessel to the stern of the last vessel towed exceeds six hundred feet. Each of these lights shall be of the same construction and character, and shall be carried in the same position as the white light mentioned in article two (_a_) or the after range light mentioned in article two (_f_). Such steam vessel may carry a small white light abaft the funnel or aftermast for the vessel towed to steer by, but such light shall not be visible forward of the beam. Lights for sailing vessels and vessels in tow. ART. 5. A sailing vessel under way or being towed shall carry the same lights as are prescribed by article two for a steam vessel under way, with the exception of the white lights mentioned therein, which they shall never carry. Lights for ferryboats, barges, and canal boats in tow. SEC. 2. That the supervising inspectors of steam vessels and the Supervising Inspector-General shall establish such rules to be observed by steam vessels in passing each other and as to the lights to be carried by ferryboats and by barges and canal boats when in tow of steam vessels (and as to the lights and day signals to be carried by vessels, dredges of all types, and vessels working on wrecks by [or] other obstruction to navigation or moored for submarine operations, or made fast to a sunken object which may drift with the tide or be towed) not inconsistent with the provisions of this act, as they from time to time may deem necessary for safety, which rules when approved by the Secretary of Commerce are hereby declared special rules duly made by local authority, as provided for in article thirty of chapter eight hundred and two of the laws of eighteen hundred and ninety. Two printed copies of such rules shall be furnished to such ferryboats (barges, dredges, canal boats, vessels working on wrecks) and steam vessels, which rules shall be kept posted up in conspicuous places in such vessels (barges, dredges, and boats). Lights for small vessels.