Age-period-cohort analysis in the 1870s: Diagrams, stereograms, and the basic differential equation

The period 1868–1880 saw a dramatic development in analytical and graphical descriptions of mortality, varying with time and age; this took place almost entirely in the German language. This report attempts a survey of these developments with brief notes on other graphical representations and on how they evolved into the Lexis diagram and the McKendrick–Von Foerster equation of the present time.