Power to fix the standard of weights and measures is vested in congress by the constitution in plain and unambiguous terms, and it was never doubted, certainly not until within a recent period, that the power conferred to coin money or to fabricate and stamp coins from gold and silver, which in the constitutional sense is the same thing, together with the power to determine the fineness, weight, and denominations of the moneys coined, was intended to accomplish the same purpose as to values. Indubitably it was so understood by congress in prescribing the various regulations contained in the act establishing the national mint, and it continued to be so understood by all branches of the government--executive, legislative, and judicial--and by the whole people of the United States, for the period of seventy years from the passage of that act. New regulations became necessary, and were passed in the meantime, increasing slightly the proportion of alloy used in fabricating the gold coins, but if those enactments are carefully examined, it will be found that no one of them contains anything inconsistent in principle with the views here expressed. Gold, at the time the act establishing the mint became a law, was valued 15 to 1 as compared with silver, but the disparity in value gradually increased, and to such an extent that the gold coins began to disappear from circulation, and, to remedy that evil, congress found it necessary to augment the _relative_ proportion of alloy by diminishing the required amount of gold, whether pure or standard. Eagles coined under that act were required to contain each two hundred and thirty-two grains of pure gold, or two hundred and fifty-eight grains of standard. Three years later congress enacted that the standard for both gold and silver coins should thereafter be such that, of one thousand parts by weight, nine hundred should be of pure metal and one hundred of alloy, by which the gross weight of the dollar was reduced to four hundred and twelve and a half grains, but the fineness of the coins was correspondingly increased, so that the money unit remained of the same intrinsic value as under the original act. Apply that rule to the eagle, and it will be seen that its gross weight would be increased, as it was in fact by that act, but it continued to contain, as under the preceding act, two hundred and thirty grains of pure gold and no more, showing conclusively that no change was made in the value of the coins. Double eagles and gold dollars were authorized to be "struck and coined" at the mint, by the act of March 3, 1849, but the standard established for other gold coins was not changed, and the provision was that the new coins should also be legal tender for their coined value.