Series Is Presented Here As Two Variables--(1)--Seasonally Adjusted, 1919-1940 (2)--Seasonally Adjusted, 1947-1963. 1919-1923 Data Are For 16 Industries; 1923-1940 Data Are For 23 Industries. Data For 1919-1922 Were Raised To The Level Of The 1923-1940 Segment (Of 23 Industries) By The Ratio Of January 1923 Covering 16 Industries To January 1923 Covering 23 Industries (See Source For More Details.) Source: G.H. Moore, Business Cycle Indicators, Vol. 2, NBER
This NBER data series m16055a appears on the NBER website in Chapter 16 at http://www.nber.org/databases/macrohistory/contents/chapter16.html.
NBER Indicator: m16055a
Release: NBER Macrohistory Database
National Bureau of Economic Research, Cumulated Net Diffusion Index, Industrial Production, 16-24 Industries, One Month Span for United States [M1655AUSM272SNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/M1655AUSM272SNBR/, September 4, 2015.