At the roots of Gini's transvariation: Extracts from "il concetto di transvariazione e le sue prime applicazioni"

The paper provides the formulations of the concept of ``Transvariation'' as Gini originally conceived in his work published in Italian in 1916 and entitled ``Il concetto di transvariazione e le sue prime applicazioni''. To offer a relatively easy reading, we selected all the main concepts and opted from a translation that sometimes deviates from the original text, but the structure and the main ideas of Gini's original article are preserved. The paper emphasizes how Gini's proposed measures of transvariation anticipated the modern analysis of distributions' overlapping.