itional white
light similar in construction to the light mentioned in subdivision
(_a_). These two lights shall be so placed in line with the keel
that one shall be at least 15 feet higher than the other, and in such a
position with reference to each other that the lower light shall be
forward of the upper one. The vertical distance between these lights
shall be less than the horizontal distance.

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 6 feet apart, and when towing more than
one vessel shall carry an additional bright white light 6 feet above or
below such light, if the length of the tow measuring from the stern of
the towing vessel to the stern of the last vessel towed exceeds 600
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 2 (_a_), excepting the additional light, which
may be carried at a height of not less than 14 feet above the hull.

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.

ART. 4. (_a_) A vessel which from any accident is not under command
shall carry at the same height as a white light mentioned in article 2
(_a_), where they can best be seen, and if a steam vessel in lieu
of that light, two red lights in a vertical line one over the other, not
less than 6 feet apart, and of such a character as to be visible all
around the horizon at a distance of at least 2 miles, and shall by day
carry in a vertical line one over the other, not less than 6 feet apart,
where they can best be seen, two black balls or shapes each 2 feet in
diameter.

(_b_) A vessel employed in laying or in picking up a telegraph
cable shall carry in the same position as the white light mentioned in
articles (_a_), and if a steam vessel in lieu of that light, three
lights in a vertical line one over the other, not less than 6 feet
apart. The highest and lowest of these lights shall be red and the
middle light shall be white, and they shall be of such a character as to
be visible all around the horizon at a distance of at least 2 miles. By
day she shall carry in a vertical line one over the other, not less t