442 FIFTY-SEOON D CONGRESS. Sess. ll. Ch. 82. 1893. opening of a draw is delayed by reason of the passing of a train after the signal has been given from a boat ready to pass through, the draw shall be opened for the passage of such boat before another train is allowed to pass over the said span or spans; nor shall there be any unnecessary delay in the passage of trains over the bridge. Phrn- Sec. 4. That all piers shall be built as nearly as may be parallel with the current of the river at that stage of water which is most important for navigation, and the bridge itself shall be built as nearly as may be at right angles thereto; and that riprapping or other protection for imperfect foundations which will lessen the required water way shall not be permitted; and also that piers which will produce cross currents or bars dangerous to navigation shall not be constructed; and if after construction any piers or accessory works are found to produce the above-mentioned eifects, or if any riprapping or other protection prohibited by this section, is found to exist, the nuisance shall be abated or corrected under the direction of the Secretary of War at the expense of the company or person owning, controlling, or operating said bridge. Awww SEO. 5. That the approaches to said bridge shall be so designed and constructed as not to interfere with the free discharge of said river in _ seasons of flood ; and any encroachment on the high-water cross section l _ by piers, solid embankments, or otherwise which will result in unduly accelerating the high-water current at the site of the bridge shall not be allowed. AMW, my-ages.,,., Sec. 6. That any corporation, company, or persons owning, control- ‘ ling,or operating the bridge, built under the authority of this act, shall build and maintain at all times as accessory work to such bridge, such booms, piers, dikes, guard fences, and similar devices, as may be nec- ‘ essary to insure at all times a permanent channel for a sufficient distance above and below the bridge site, and for the guiding of rafts, steamboats, and other water craft safely under or through said bridge; and if at any time after the construction of the bridge and its acces sory works the approaches to draw openings, channel spans, or raft passages in said bridge are found to be dangerous or ditiicult of access by river trailic the Secretary of War may, upon the recommendation of the Chief of Engineers, United States Army, order the corporation, company, or persons owning, controlling, or operating said bridge to construct, under his directions, and to maintain such additional sheer booms, dikes, and other devices as will obviate the difficulty mentioned, which additional sheer booms, dikes, and other devices shall be built and maintained at their own expense by said company or persons; Lsguuteie. and that said company or persons shall maintain, at their own expense, from sunset to sunrise such lights and other signals on said bridge as may be required by the Light-House Board for the security of navigation. Secretary of wu to Sec. 7. That the bridge authorized to be constructed by this act shall °¥‘l"°'° *"‘““‘·°*°· be located and built under and subject to such regulations for the security of navigation on said river as the Secretary of War shall prescribe; and to secure that object said corporation shall submit for his examination a design and drawing of the bridge, piers, approaches, and accessory works, and a map of the location, giving for a space of one mile above and one mile below the proposed location the topography of the banks of the river and the shore lines at high and low water. This map shall be accompanied by another, drawn on the scale of one inch to two hundred feet, giving for a space of one-half mile above the line of the proposed bridge and one—quarter mile below an accurate representation of the bottom of the river, by contour lines live feet apart, determined by accurate soundings, and also showing over the whole width of this part of the river the force and direction of the currents at low water, at high water, and at least one intermediate stage by triangulated observations on suitable floats. The maps shall also show the location of other bridges in the vicinity, and shall give such information as the Secretary of War may require for a full and satisfactory
