Statutes making eight hours a day's labor for work- men, laborers, and mechanics. Laws limiting the hours of toil of em- ployees, (such as laborers, workmen, mechan- ics, etc.), to eight hours in any one calendar day, without reduction of compensation for the day's services. 60 Kan. 106. Eight hours shall constitute a day's work for all laborers, workmen, and mechanics who may be employed by or on behalf of the United States. R.S. § 3738. This act is not a contract between the government and its laborers that eight hours shall constitute a day's work. It neither prevents the government from making agreements with them, by which their labor may be more or less than eight hours a day, nor does it prescribe the amount of compensation for that or any other number of hours' labor ; 94 U. S. 400. On May 24, 1888, a law was passed direct- ing that eight hours should constitute a day's work for letter-carriers in the United States, and for time worked in excess of that number of hours they should be paid extra (25 Stat. L. 157). Under this statute the supreme court held that a letter-carrier was entitled to eight hours' work each day, and that over time on one day could not be set off against a deficiency on another; 148 U. S. 134. See FACTORY ACT. In United States Statute. The Act of August 1, 1892, с. 352, 27 Stat. 340 limits the service and employment of all laborers and mechanics employed by the United States, by the District of Columbia, or by any contractor or subcontractor upon any of the public works of the United States or the District, to eight hours in any one calendar day, and makes it unlawful "to require or permit any such laborer or mechanic to work more than eight hours in any calendar day except in case of extraor- dinary emergency," and imposes penalties for the violation thereof. 206 U. S. 254, 255. The provisions of this act were held constitu- tional and within the powers of Congress. In this respect Congress has the same power as a State has over the construction of its public works. Id., citing 191 U. S. 207.