MURPHY, J., dissenting. 330 U.S. Yet the nature of some acts is such that a non-treasonous motive cannot be completely dismissed as a possibility. An overt act of treason, however, should rest upon something more substantial than a reasonable doubt. Treason is different from ordinary crimes, possessing unique and difficult standards of proof which confine it within narrow spheres. It has such serious connotations that its substance cannot be left to conjecture. Only when the alleged overt act manifests treason beyond all reasonable doubt can we be certain that the traitor's stigma will be limited to those whose actions constitute a real threat to the safety of the nation. Tested by that standard, the conviction in the instant case cannot be sustained. Petitioner, it is said, had the misfortune to sire a traitor. That son lived with petitioner and his wife in their Chicago apartment. After a sojourn in Germany for training as a saboteur, the son returned to the Chicago apartment and began to make preparations to carry out his mission of sabotage. It is claimed that petitioner knew of his son's activities and desired to help him. For six days prior to his arrest, the soh lived in petitioner's apartment; he was not secreted in any way, coming and going as he normally would have done. The indictment alleged that petitioner committed an overt act of treason by sheltering and harboring his son for those six days. Concededly, this was a natural act for a father to perform; it is consistent with parental devotion for a father to shelter his son, especially when the son ordinarily lives with the father. But the Court says that the jury might find, under appropriate instructions, that petitioner provided this shelter, not merely as an act of an indulgent father toward a disloyal son, but as an act designed to injure the United States. A saboteur must be lodged in a safe place if his mission is to be effected and the jury might well find that petitioner lodged his son for that purpose. But the act of providing shelter was of the type that might naturally arise out of petitioner's relationship to his son, as the Court recognizes. By its very nature, therefore, it is a non-treasonous act. That is true even when the act is viewed in light of all the surrounding circumstances. All that can be said is that the problem of whether it was motivated by treasonous or non-treasonous factors is left in doubt. It is therefore not an overt act of treason, regardless of how unlawful it might otherwise be. LEVINSON v. SPECTOR MOTOR SERVICE. CERTIORARI TO THE SUPREME COURT OF ILLINOIS. No. 22. Argued December 11, 1945. Reargued October 21, 22, 1946. Decided March 31, 1947. 1. The Interstate Commerce Commission "has power," under § 204 of the Motor Carrier Act, 1935, to establish qualifications and maximum hours of service with respect to a "checker" or "terminal foreman," a substantial part of whose activities consists of doing, or immediately directing, the work of one or more "loaders" of freight for an interstate motor carrier, as such class of work has been defined by the Commission and found by it to affect the safety of operation; and such an employee is expressly excluded by § 13 (b) (1) of the Fair Labor Standards Act from the overtime compensation requirements of § 7, although the Commission has not exercised its power affirmatively by establishing qualifications and maximum hours of service with respect to "loaders." Pp. 651-653, 670-685. 2. In order to establish that an employee is excluded by § 13 (b) (1) of the Fair Labor Standards Act from a right to increased pay for overtime services under §7, it is not necessary as a condition precedent to find that the Commission has exercised or should exercise its power to establish qualifications and maximum hours of service. The existence of the power is enough. P. 678. 3. From the point of view of the Commission and its jurisdiction over safety of operation, it is the character of an employee's activities rather than the proportion of his time or of his activities that determines the need for the Commission's power to establish quali fications and maximum hours of service. Pp. 674-675. [See also Pyramid Motor Freight Corp. v. Ispass, post, p. 695.] 4. For the purposes of this case, it is enough that a substantial part of the employee's activities consisted of doing, or immediate direction of, the very kind of activities of a "loader" which the Commission found to affect safety of operation—although it does not appear what fraction of his time was spent in such activities. P. 681. 5. The scope of the power of the Commission under § 204 to establish qualifications and maximum hours of service with respect to classes of employees of interstate motor carriers depends upon an interpretation of that section in accordance with the purposes of the Motor Carrier Act and the regulations issued pursuant to it— not upon a restrictive interpretation of the exemption created by § 13 (b) (1) of the Fair Labor Standards Act. Pp. 676-677. 6. In reconciling these two Acts, it is necessary to put safety first and to limit the authority of the Wage and Hour Administrator to those employees of motor carriers whose activities do not affect the safety of operation. P. 677. 7. The Wage and Hour Administrator has no authority to expand his jurisdiction under the Fair Labor Standards Act by administrative interpretations which reduce the jurisdiction of the Commission under the Motor Carrier Act. P. 684. 389 Ill. 466, 59 N. E. 2d 817, affirmed. An employee of an interstate motor carrier obtained judgment in a state court for unpaid overtime compensation under the Fair Labor Standards Act. The Appellate Court of Illinois reversed. 323 Ill. App. 505, 56 N. E. 2d 142. The Supreme Court of Illinois affirmed. 389 Ill. 466, 59 N. E. 2d 817. This Court granted certiorari. 326 U. S. 703. Affirmed, p. 685. Harry L. Yale argued the cause for petitioner. With him on the brief was Richard S. Folsom. David Axelrod argued the cause for respondent on the original argument and Roland Rice on the reargument. With them on the briefs were Harry J. Lurie and Maurice P. Golden. Peter T. Beardsley was also on the brief on the reargument. 649 Opinion of the Court. By special leave of Court, Jeter S. Ray argued the cause for the Administrator of the Wage and Hour Division, United States Department of Labor, as amicus curiae, on the reargument. With him on the brief was William S. Tyson. By special leave of Court, Daniel W. Knowlton argued the cause and filed a brief for the Interstate Commerce Commission, as amicus curiae, on the reargument. Solicitor General McGrath filed a memorandum, as amicus curiae, on the original argument. MR. JUSTICE BURTON delivered the opinion of the Court. This case presents the question whether the Interstate Commerce Commission has the power, under § 204 of the Motor Carrier Act, 1935,1 to establish qualifications and maximum hours of service with respect to any "checker" or "terminal foreman," a substantial part of whose activities in that capacity consists of doing, or immediately 1 The material parts of § 204 are: "SEC. 204 (a) It shall be the duty of the Commission— "(1) To regulate common carriers by motor vehicle as provided in this part, and to that end the Commission may establish reasonable requirements with respect to continuous and adequate service, transportation of baggage and express, uniform systems of accounts, records, and reports, preservation of records, qualifications and maximum hours of service of employees, and safety of operation and equipment. "(2) To regulate contract carriers by motor vehicle as provided in this part, and to that end the Commission may establish reasonable requirements with respect to uniform systems of accounts, records, and reports, preservation of records, qualifications and maximum hours of service of employees, and safety of operation and equipment. "(3) To establish for private carriers of property by motor vehicle, if need therefor is found, reasonable requirements to promote safety of operation, and to that end prescribe qualifications and maximum hours of service of employees, and standards of equipment. . . ." (Italics supplied.) 49 Stat. 546, 49 U. S. C. § 304 (a) (1), (2) and (3). Opinion of the Court. 330 U.S. directing, the work of one or more "loaders" of freight for an interstate motor carrier as such class of work is defined by the Interstate Commerce Commission in Ex parte No. MC-2, 28 M. C. C. 125, 133-134,2 although the rest of his activities do not affect the safety of operation of any such motor carrier.3 2"(2) Loaders. "The large carriers, particularly those who have important operations from terminal to terminal, employ men variously called loaders, dockmen, or helpers, and hereinafter called loaders, whose sole duties are to load and unload motor vehicles and transfer freight between motor vehicles and between the vehicles and the warehouse. "The evidence makes it entirely clear that a motor vehicle must be properly loaded to be safely operated on the highways of the country. If more weight is placed on one side of the vehicle than on the other, there is a tendency to tip when rounding curves. If more weight is placed in the rear of the vehicle, the tendency is to raise the front wheels and make safe operation difficult. Further, it is necessåry that the load be distributed properly over the axles of the motor vehicle. "Proper loading is not only necessary when heavy machinery, steel, and other like commodities are being transported, but is of importance when normal package freight is handled. If several packing cases weighing from 150 to 200 pounds are loaded on one side of a motor vehicle or at one end thereof, and lighter freight on the other side or at the other end, safe operation is difficult. The great majority, if not all, of the carriers whose operations are of sufficient size or character to justify the employment of loaders handle freight of such weight that proper loading is necessary." Ex parte No. MC-2, 28 M. C. C. 125, 133-134. Throughout this case it has been recognized that it was within the power of the Commission to establish the qualifications and maximum hours of service for the regular "loaders" who served under the immediate direction of the petitioner. No claim has been made on their behalf to the benefits of § 7 of the Fair Labor Standards Act. The present controversy is limited to the status of the petitioner himself. His status is referred to throughout this opinion as that of a "partial-duty loader," except where he is referred to by his own designation of himself as a "checker" or "terminal foreman." The term "partial-duty loader" is used in preference to that of "part |