The Commission shall have full authority and power at any time to institute an inquiry, on its own motion, in any case and as to any matter or thing concerning which complaint is authorized to be made, to or before the Commission by any provision of this chapter, or concerning which any question may arise under any of the provisions of this chapter, or relating to the enforcement of any of the provisions of this chapter. The Commission shall have the same powers and authority to proceed with any inquiry instituted on its own motion as though it had been appealed to by complaint or petition under any of the provisions of this chapter, including the power to make and enforce any order or orders in the case, or relating to the matter or thing concerning which the inquiry is had, excepting orders for the payment of money.

Whenever an investigation shall be made by the Commission it shall be its duty to make a report in writing in respect thereto, which shall state the conclusions of the Commission, together with its decision, order, or requirement in the premises; and in case damages are awarded such report shall include the findings of fact on which the award is made.

The district courts of the United States shall have jurisdiction upon the relation of any person alleging any violation, by a carrier subject to this chapter, of any of the provisions of this chapter which prevent the relator from receiving service in interstate or foreign communication by wire or radio, or in interstate or foreign transmission of energy by radio, from said carrier at the same charges, or upon terms or conditions as favorable as those given by said carrier for like communication or transmission under similar conditions to any other person, to issue a writ or writs of mandamus against said carrier commanding such carrier to furnish facilities for such communication or transmission to the party applying for the writ: Provided, That if any question of fact as to the proper compensation to the carrier for the service to be enforced by the writ is raised by the pleadings, the writ of peremptory mandamus may issue, notwithstanding such question of fact is undetermined, upon such terms as to security, payment of money into the court, or otherwise, as the court may think proper pending the determination of the question of fact: Provided further, That the remedy given by writ of mandamus shall be cumulative and shall not be held to exclude or interfere with other remedies provided by this chapter.

If a carrier does not comply with an order for the payment of money within the time limit in such order, the complainant, or any person for whose benefit such order was made, may file in the district court of the United States for the district in which he resides or in which is located the principal operating office of the carrier, or through which the line of the carrier runs, or in any State court of general jurisdiction having jurisdiction of the parties, a petition setting forth briefly the causes for which he claims damages, and the order of the Commission in the premises. Such suit in the district court of the United States shall proceed in all respects like other civil suits for damages, except that on the trial of such suits the findings and order of the Commission shall be prima facie evidence of the facts therein stated, except that the petitioner shall not be liable for costs in the district court nor for costs at any subsequent stage of the proceedings unless they accrue upon his appeal. If the petitioner shall finally prevail, he shall be allowed a reasonable attorney’s fee, to be taxed and collected as a part of the costs of the suit.

Except as otherwise provided in this chapter, all orders of the Commission, other than orders for the payment of money, shall take effect thirty calendar days from the date upon which public notice of the order is given, unless the Commission designates a different effective date. All such orders shall continue in force for the period of time specified in the order or until the Commission or a court of competent jurisdiction issues a superseding order.

The copies of schedules of charges, classifications, and of all contracts, agreements, and arrangements between common carriers filed with the Commission as herein provided, and the statistics, tables, and figures contained in the annual or other reports of carriers and other persons made to the Commission as required under the provisions of this chapter shall be preserved as public records in the custody of the secretary of the Commission, and shall be received as prima facie evidence of what they purport to be for the purpose of investigations by the Commission and in all judicial proceedings; and copies of and extracts from any of said schedules, classifications, contracts, agreements, arrangements, or reports, made public records as aforesaid, certified by the secretary, under the Commission’s seal, shall be received in evidence with like effect as the originals: Provided, That the Commission may, if the public interest will be served thereby, keep confidential any contract, agreement, or arrangement relating to foreign wire or radio communication when the publication of such contract, agreement, or arrangement would place American communication companies at a disadvantage in meeting the competition of foreign communication companies.

It shall be the duty of every carrier subject to this chapter to designate in writing an agent in the District of Columbia, upon whom service of all notices and process and all orders, decisions, and requirements of the Commission may be made for and on behalf of said carrier in any proceeding or suit pending before the Commission, and to file such designation in the office of the secretary of the Commission, which designation may from time to time be changed by like writing similarly filed; and thereupon service of all notices and process and orders, decisions, and requirements of the Commission may be made upon such carrier by leaving a copy thereof with such designated agent at his office or usual place of residence in the District of Columbia, with like effect as if made personally upon such carrier, and in default of such designation of such agent, service of any notice or other process in any proceeding before said Commission, or of any order, decision, or requirement of the Commission, may be made by posting such notice, process, order, requirement, or decision in the office of the secretary of the Commission.

Nothing in this chapter contained shall in any way abridge or alter the remedies now existing at common law or by statute, but the provisions of this chapter are in addition to such remedies.