_Provided, however_, That nothing in the provisions of this Title shall prohibit the transportation by vessels not carrying passengers for hire, of gasoline or any of the products of petroleum for use as a source of motive power for the motor boats or launches of such vessels. (May 28, 1906.) _Provided further_, That nothing in the foregoing or following sections of this Act shall prohibit the use, by steam vessels carrying passengers for hire, of lifeboats equipped with gasoline motors, and tanks containing gasoline for the operation of said motor-driven lifeboats: _Provided, however_, That no gasoline shall be carried other than that in the tanks of the lifeboats: _Provided further_, That the use of such lifeboats equipped with gasoline motors shall be under such regulations as shall be prescribed by the board of supervising inspectors with the approval of the Secretary of Commerce. (Jan. 24, 1913.) _Provided, however_, That nothing in the foregoing or following sections of this Act shall prohibit the transportation and use by vessels carrying passengers or freight for hire of gasoline or any of the products of petroleum for the operation of engines to supply an auxiliary lighting and wireless system independent of the vessel's main power plant: _Provided further_, That the transportation or use of such gasoline or any of the products of petroleum shall be under such regulations as shall be prescribed by the Board of Supervising Inspectors, with the approval of the Secretary of Commerce. (R. S., 4472; Oct. 22, 1914.) Every bale of cotton or hemp that shall be shipped or carried on any passenger-steamer, without conforming to the provisions of the preceding section, shall be subject to a penalty of five dollars, and shall be liable to seizure and sale to secure the payment of such penalty. (R. S., 4473.) The Secretary of Commerce may grant permission to the owner of any steam vessel, to use any invention or process for the utilization of petroleum or other mineral oils or substances in the production of motive-power, and may make and enforce regulations concerning the application and use of the same for such purpose. But no such permission shall be granted, unless upon the certificate of the supervising inspector of steamboats for the district wherein such vessel is registered, and other satisfactory proof that the use of the same is safe and efficient; and upon such proof, and the approval of such certificate by the Secretary of Commerce, a special license for the use of such process or invention shall issue under the seal of the Department of Commerce. (R. S., 4474; Feb. 14, 1903; sec. 10.)