It is really an amazing story! > But copper—used in shell casings—was a high-priority commodity during the war. So Marshall and Nichols struck on the idea of u

It is really an amazing story! > But copper—used in shell casings—was a high-priority commodity during the war. So Marshall and Nichols struck on the idea of using silver as a substitute. Congress had authorized the use of up to 86,000 tons of Treasury Department silver for defense purposes. (...) > Nichols met with Undersecretary of the Treasury Daniel Bell on August 3, 1942, to inquire about borrowing 6,000 tons of silver from Treasury vaults. In his memoirs, Nichols relates that Bell indignantly informed him that the Treasury’s unit of measure was the troy ounce—though not all present at that meeting recall any unpleasantness. (...) > Scrap recovery and cleanup operations were so successful that over the course of processing, more than 1.5 million pounds of silver were collected and returned to Treasury, much of it likely originating from earlier and unrelated silver processing. That more than offset a much smaller amount—11,000 pounds—of borrowed Treasury silver that was unaccounted for. (...) > The busbars were massive conductors about a foot square that carried current to the magnet coils. During their manufacture, armed guards again stood by, this time with pieces of paper positioned to catch drill dust as workmen bored holes in pieces of silver in preparation for fastening them together. https://www.americanscientist.org/article/from-treasury-vault-to-the-manhattan-project https://www.americanscientist.org/article/from-treasury-vaul...