FIFTY-FOURTH CONGRESS. Sess. I. Ch. 414. 1896. 387 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 waterway 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 effects, 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 persons owning, controlling, or operating said bridge. " Sec. 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 by piers, solid embankments, or otherwise which will result in unduly accelerating the high-water current at the site of the bridge will not be allowed. _ 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 works to such bridge, such booms, piers, dikes, guard fences, and similar devices as may be necessary to insure at all times a permanent channel for a sudicient 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 accessory works the approaches to draw openings, channel spans, or raft passages in said bridge are found to be dangerous or difficult of access by river trailic the Secretary of War may, upon the recommendation of the Chief of Engineers, United State 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; and that L*H*=*=· ¤*¤· said company or persons shall maintain, at their own expense, from sunset to sunrise throughout the season of navigation, such lights and other signals on said bridge as may be required by the Light-House Board for the security of navigation. SEo. 7. That the bridge authorized to be constructed by this Act I $•r·j_*;_j;jY,:::{:"° shall be located and built under and subject to such regulations for the Pp' 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 drawings of the bridge, piers, approaches, and accessory works, and a map of the location giving, for a space of at least three miles above and one mile below the proposed location, the topography of the banks of said river and the shore lines at high and low water. This map shall be accompanied by others drawn on the scale of one inch to two hundred feet, giving, for a space of one-half of a mile above the line of the proposed bridge and one-quarter of a mile below, an accurate representation of the bottom of the river, by contour lines five 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 triangulatcd 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 understanding of the subject; and the construction of the proposed bridge shall not be commenced until the location and plans thereof are approved by the Secretary of War. Sec. 8. That any bridge constructed under the authority of this Act supsmnim. shall be built under the general supervision of the Secretary of War, and no changes or alterations in plans shall be made during the construction of said bridge or after its completion unless said changes or cmmswalterations conform to the provisions of this Act and are authorized by
