Query: 1913 "steams"

[Gerald Cohen]

    I'm puzzled by "steams" in the following quote:

    "They're going to charge only $200 a seat at the big polo match at
Newport, which shows that sport to be an extremely cheap one.  The
purchasing power of $200 is only 4000 'steams'."

(in:  _San Francisco Bulletin_, March 29, 1913, p.27; "Sporting
Tit-Bits by 'Mac'", an eclectic sports column. The above brief quote
is the entire item)

--- If $200 is equated with 4000 "steams," a single  "steam" would be
a nickel. But this meaning of "steam" is apparently not attested in
the dictionaries, and is the quote in fact equating $200 and 4000
nickels? And if it is, how did "steams" get this meaning?

    Would anyone have an idea on this?

---Gerald Cohen