The Secretary of Commerce may permit the use of petroleum as fuel on steamers not carrying passengers, without the certificate of the supervising inspector of the district where the vessel is to be used, subject to such conditions and safeguards as the Secretary of Commerce in his judgment shall provide. For a violation of any of the conditions imposed by the Secretary of Commerce a penalty of five hundred dollars shall be imposed, which penalty shall be a lien upon the vessel, but a bond may, as provided in other cases, be given to secure the satisfaction of the judgment. (Oct. 18, 1888; Feb. 14, 1903; sec. 10.) _Provided further_, That when crude petroleum of a flash point not less than one hundred and fifty degrees Fahrenheit, is carried in the double-bottom fuel tanks of steamers using the same for fuel, the crude petroleum carried in such tanks in excess of the necessities of the voyage may be discharged at terminal ports when no passengers are on board the ship. Crude petroleum carried and discharged under these conditions will not be considered stores or cargo within the contemplation of section forty-four hundred and seventy-two, Revised Statutes of the United States. (R. S., 4474.) All gunpowder, nitro-glycerine, camphene, naphtha, benzine, benzole, coal-oil, crude or refined petroleum, oil of vitriol, nitric or other chemical acids, oil or spirits of turpentine, friction-matches, and all other articles of like character, when packed or put up for shipment, shall be securely packed and put up separately from each other and from all other articles; and the package, box, cask, or other vessel containing the same shall be distinctly marked on the outside, with the name or description of the article contained therein. It shall be unlawful to transport, carry, or convey, liquid nitro-glycerine, fulminate in bulk in dry condition, or other like explosive, between a place in a foreign country and a place within or subject to the jurisdiction of the United States, or between a place in one State, Territory, or District of the United States, or place noncontiguous to but subject to the jurisdiction thereof, and a place in any other State, Territory, or District of the United States, or place noncontiguous to but subject to the jurisdiction thereof, on any vessel or vehicle of any description operated by a common carrier in the transportation of passengers or articles of commerce by land or water. (R. S., 4475.)