The Drake Plate of Brass — a club’s private joke that a famous historian mistook for treasure

In 1936 a young store clerk named Beryle Shinn picked up a corroded brass rectangle near San Francisco Bay, and the following spring the most distinguished historian of the Spanish borderlands in America, Herbert Eugene Bolton of the University of California, Berkeley, announced it to the world as one of history’s lost treasures. The plate appeared to be the brass tablet that Sir Francis Drake had nailed to a post in 1579 to claim “Nova Albion” — the California coast — for Queen Elizabeth I. Bolton declared on 6 April 1937 that “the authenticity of the tablet seems to me beyond all reasonable doubt,” and the California Historical Society bought it for $3,500. It became a centerpiece of the Bancroft Library and a fixture of California’s founding story for forty years.

It was a fraud, and an accidental one. The plate had been manufactured around 1933 by members of E Clampus Vitus, a jovial California fraternity of history enthusiasts, as a private practical joke aimed at Bolton, himself a member, who was known to dream of finding Drake’s plate. The hoaxers even painted the initials “ECV” on the back in fluorescent paint, invisible in ordinary light, intending Bolton to discover the gag once he turned the plate over under ultraviolet. He never did. By the time the plate surfaced in his office, the joke had escaped its makers’ control, and none of them could find a way to confess without humiliating a colleague and a major institution.

The forgery was finally and definitively exposed in 1977, when Helen Michel and Frank Asaro of the Lawrence Berkeley Laboratory subjected the metal to neutron activation analysis. The brass contained far more zinc than any sixteenth-century alloy — zinc was not isolated and added to brass deliberately until centuries after Drake — and far too little of the trace nickel, lead, gold, and iron that period brass carried. X-ray and gamma-ray tests showed the plate had been rolled smooth by modern machinery, not hammered by hand. The metal was modern American brass, most likely made between the late nineteenth and early twentieth centuries. In 2002–03, historians Edward Von der Porten, Raymond Aker, Robert W. Allen, and James M. Spitze published the full reconstruction of who made the plate and why.

The case is a study in how a respected expert’s longing for a particular discovery can override every warning sign. Doubts about the plate’s spelling, lettering, and manufacture were raised almost immediately, yet the authority of Bolton’s name carried it past them for a generation. The joke’s intended punchline — the hidden “ECV” — sat on the object the whole time, unread.