United States to the laws of the State or Territory in which the court is held.

It was not the purpose of § 724 to interpose an obstacle to the exercise of the general power of the court with respect to the issuance of subpoenas duces tecum, and that was not its effect. The barrier, in the case of parties, existed independently of the provisions of the section and by these it was sought to mitigate the resulting inconvenience. When, however, the rule as to parties was changed it followed that the obstacle was removed and by virtue of the general authority of the court subpoenas duces tecum may run to parties as well as to others,-leaving those who are subpœnæd to attack the process if of improper scope or lacking in definiteness, or to assert against its compulsion whatever privileges they may enjoy. See Merchants' National Bank v. State National Bank, 3 Cliff. 203, 204; Nelson v. United States, 201 U. S. 92.

We conclude, therefore, that no question arises under § 724, which cannot be regarded as providing an exclusive procedure. The subpoena was valid; and the books called for were produced. The inquiry, then, is as to the admissibility of the entries.

It is insisted that the evidence was inadmissible under § 860 of the Revised Statutes. This ground, although it had been relied upon earlier in the trial, was not included in the objection-as it was formally stated at lengthwhen the books were finally produced and the entries offered. But, apart from this, the statute did not afford a sufficient basis for objection.

Section 860-since repealed by the act of May 7, 1910, ch. 216 (36 Stat. 352),--was a reënactment of § 1 of the act of February 25, 1868, ch. 13 (15 Stat. 37), and provided:

"SEC. 860. No pleading of a party, nor any discovery or evidence obtained from a party or witness by means of a judicial proceeding in this or any foreign country, shall

be given in evidence, or in any manner used against him or his property or estate, in any court of the United States, in any criminal proceeding, or for the enforcement of any penalty or forfeiture: Provided, That this section shall not exempt any party or witness from prosecution and punishment for perjury committed in discovering or testifying as aforesaid."

This language is inapposite here, for it manifestly refers to a case where, in some prior judicial proceeding, discovery had been made or testimony had been given and the evidence so obtained was sought to be used. The object of the statute is sufficiently plain. It was intended to give immunity as to subsequent proceedings to the one making discovery or testifying. But it was held to be inadequate, because it was not co-extensive with the constitutional privilege. Counselman v. Hitchcock, 142 U. S. 547, 564; Brown v. Walker, 161 U. S. 594.

In the present case, the question, therefore, must be whether under the Fourth and Fifth Amendments of the Constitution of the United States the defendant Company, as it contends, was entitled to object to the admission in evidence of the entries from its books. As to this, we need only refer to the recent decisions of this court. Hale v. Henkel, 201 U. S. 43; Nelson v. United States, supra; Hammond Packing Company v. Arkansas, 212 U. S. 348, 349; Wilson v. United States, decided May 15, 1911, ante, p. 361.

We have examined the errors assigned with respect to other rulings on questions of evidence and the refusal of the court to direct a verdict for the defendant, and we find no ground for a reversal of the judgment.

Affirmed.

BALTIMORE AND OHIO RAILROAD COMPANY

v. INTERSTATE COMMERCE COMMISSION.

APPEAL FROM THE CIRCUIT COURT OF THE UNITED STATES FOR THE DISTRICT OF MARYLAND.

No. 222. Argued April 17, 18, 1911.-Decided May 29, 1911.

The act of March 4, 1907, 34 Stat. 145, c. 2939, regulating the hours

of labor of railway employés engaged in interstate commerce and requiring carriers to make reports in regard thereto, is not unconstitutional as beyond the power of Congress because it applies to railroads and employés engaged in intrastate business. Employers' Liability Cases, 207 U. S. 463, distinguished.

By virtue of its power to regulate interstate and foreign commerce Congress may enact laws for the safeguarding of persons and property in interstate transportation and may restrict the hours of labor of employés connected with such transportation.

The length of time employed has a direct relation to efficiency of employés, and the imposition of reasonable restrictions in regard thereto is not an unconstitutional interference with the liberty of contract. C., B. & Q. R. R. Co. v. McGuire, 219 U. S. 549.

The power of Congress to make regulations in regard to agencies for interstate commerce is not defeated by the fact that the agencies regulated are also connected with intrastate commerce.

An exception in a statute of cases of emergency does not render a statute void for uncertainty where Congress has appropriately described the exceptional cases intended to be covered. Under 4 of the Act to Regulate Commerce the Interstate Commerce Commission has power to require carriers to make reports regarding the hours of labor of such employés as are subject to the act of March 4, 1907, and the requirement of such reports does not constitute an unreasonable search or seizure within the meaning of the Fourth Amendment.

A corporation cannot plead a privilege against self-incrimination under the Fifth Amendment; nor can an officer of a corporation plead that the immunity guaranteed by that amendment relieves him personally from making records from the books and papers of the corporation. Wilson v. United States, ante, p. 361.

THE facts, which involve the validity of an order made by the Interstate Commerce Commission, and the construction of the Employé's Act (hours of service) of March 4, 1907, 34 Stat. 1415, c. 2939, are stated in the opinion.

Mr. Frederic D. McKenney, with whom Mr. John G. Johnson and Mr. Hugh L. Bond, Jr., were on the brief, for appellant.

The Solicitor General for the appellee.

MR. JUSTICE HUGHES delivered the opinion of the court.

This is a bill in equity to annul an order made by the Interstate Commerce Commission on March 3, 1908, and for injunction. The order required the carriers within the provisions of the act of Congress of March 4, 1907, chapter 2939, 34 Stat. 1415, to make monthly reports, under oath, showing the instances where employés subject to that act had been on duty for a longer period than that allowed. The statute, entitled "An act to promote the safety of employés and travelers upon railroads by limiting the hours of service of employés thereon," is set forth in the margin.1

1 Be it enacted by the Senate and House of Representatives of the United States of America in Congress assembled, That the provisions of this Act shall apply to any common carrier or carriers, their officers, agents, and employés, engaged in the transportation of passengers or property by railroad in the District of Columbia or any Territory of the United States, or from one State or Territory of the United States or the District of Columbia to any other State or Territory of the United States or the District of Columbia, or from any place in the United States to an adjacent foreign country, or from any place in the United States through a foreign country to any other place in the United States. The term "railroad" as used in this Act shall include all bridges and ferries used or operated in connection with any railroad, and also all the road in use by any common carrier operating a railroad, whether

By stipulation there were introduced into the record additional instructions issued by the Commission under date of August 15, 1908. These prescribed new forms, and also a separate form of oath for use in case there had been no excessive service; and it was further directed that reports of hours of service of the employés described should be made by the secretary or similar officer of the carrier.

It was agreed that a number of like suits brought by other carriers should abide the final disposition of this cause and that meanwhile the reports should not be required.

The bill alleged that the purpose of the Commission in

owned or operated under a contract, agreement, or lease; and the term "employés" as used in this Act shall be held to mean persons actually engaged in or connected with the movement of any train.

SEC. 2. That it shall be unlawful for any common carrier, its officers or agents, subject to this Act to require or permit any employé subject to this Act to be or remain on duty for a longer period than sixteen consecutive hours, and whenever any such employé of such common carrier shall have been continuously on duty for sixteen hours he shall be relieved and not required or permitted again to go on duty until he has had at least ten consecutive hours off duty; and no such employé who has been on duty sixteen hours in the aggregate in any twentyfour-hour period shall be required or permitted to continue or again go on duty without having had at least eight consecutive hours off duty: Provided, That no operator, train dispatcher, or other employé who by the use of the telegraph or telephone dispatches, reports, transmits, receives, or delivers orders pertaining to or affecting train movements shall be required or permitted to be or remain on duty for a longer period than nine hours in any twenty-four-hour period in all towers, offices, places, and stations continuously operated night and day, nor for a longer period than thirteen hours in all towers, offices, places, and stations operated only during the daytime, except in case of emergency, when the employés named in this proviso may be permitted to be and remain on duty for four additional hours in a twentyfour-hour period on not exceeding three days in any week: Provided further, The Interstate Commerce Commission may after full hearing in a particular case and for good cause shown extend the period within