Source: Computed By NBER By Subtracting Series 13016 (London Open Market Discount Rate) From Series 13001 (New York Call Money Rate).
This NBER data series m13040 appears on the NBER website in Chapter 13 at http://www.nber.org/databases/macrohistory/contents/chapter13.html.
NBER Indicator: m13040
Release: NBER Macrohistory Database
National Bureau of Economic Research, Excess of New York Call Money Rate Over London Open Market Discount Rate [M13040M156NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/M13040M156NNBR/, November 30, 2015.