approval. According to Jesse P. Watson in his monograph on the Bureau of the Mint, the admission of members of the public to the Assay Commission meant "that permanency and high official dignity were no longer characteristic of the commission". In 1861, as the American Civil War broke out, North Carolina joined the Confederate States. The Charlotte Mint, taken over by the Confederacy, eventually closed as the dies that had been shipped from the Philadelphia Mint wore out, and it could obtain no more. Nevertheless, 12 half eagles ($5 gold coins) were sent from Charlotte to Philadelphia, through enemy lines, in October 1861. They were duly tested by the 1862 Assay Commission, and were found to be correct. In 1864, with the metal nickel, used in the cent in short supply, Mint Director James Pollock asked that year's commission to opine on a substitute for the copper-nickel used in the cent. The members endorsed French bronze (95% copper and 5% tin or zinc) as a metal to be used in the cent and a proposed two-cent piece. Pollock sent the conclusions to Treasury Secretary Salmon P. Chase, who forwarded them (and draft legislation) to Maine Senator William P. Fessenden, chairman of the Senate Finance Committee. The Coinage Act of 1864 was signed by President Abraham Lincoln on April 22, 1864. Later years (1873–1949) The Coinage Act of 1873 revised the laws relating to coinage and the Mint and retired several denominations including the two-cent piece. The act also changed the officers required to serve on the Assay Commission: The act also required the Mint to put aside one of every thousand gold coins struck, and one of every two thousand silver coins for the assay. It provided the procedure for putting the coins aside, sealing them in envelopes, and placing them in a pyx to be opened by the assay commissioners. The 1881 Assay Commission found that approximately 3,000 silver dollars struck at the Carson City Mint (1881-CC) had been struck in .892 silver rather than the legally mandated .900. It is unclear if the Treasury took any steps to attempt to recover the issued pieces. The 1885 commission detected a single silver dollar which was 1.51 grains (0.098 g) below specifications, the permitted tolerance being . In 1921, the Assay Commission found that some coins struck at the Denver Mint were struck in .905 or .906 silver, above the