In 1749 the Swedish kingdom instigated the Tabellverket (i.e Tables' Committee) with the purpose of gathering population statistics, i.e. to measure the population size, its main characteristics etc. This was the first formal statistics body to be formed in Europe. The scientists of the Royal Academy of Sciences pushed for this ambitious project and Pehr Wargentin, an astronomer and secretary of the Academy, contributed to the interpretation of the results. He wrote several memoires on population statistics. Those memoires are not known but they are essential in the history of statistics. As this year, it is 300 years anniversary of Wargentin’s birth, we would like to take this opportunity to underline the work done by this scholar focusing on the survival function and from there Wargentin had a vision of the age pyramid.

As mentioned above Pehr Wargentin focused in particular on the survival function and for the first time on inequality between men and women. Contrary to the current utility of the age pyramid, which aims to establish average durations of survival, the survival function was a way for the scholars of the time to deduce the total population. To approximate the universal multiplier or to find a more exact method to estimate the size of the population they constructed mortality with the parameters they knew as the number of births or the number of deaths. The calculations made by Wargentin and previously by Hayley are based on a stable and closed population. In this situation, the calculations allow to represent a survival curve and also a pyramid of age if one inverses x-axis and the y-axis.

The aim of this communication is to present the pyramid according to Wargentin and others views of the time as well as to put it into perspectives with actual graphical representations.