Max Ringelmann

Maximilien Ringelmann (10 December 1861, Paris – 2 May 1931, Paris)

Ringelmann's interests were wide-ranging: he developed the Ringelmann scale which is still used to measure smoke. He also discovered the Ringelmann effect in social psychology, viz, that when working in groups, individuals slacken.

Education After graduating from the public schools of Paris, Ringelmann studied at the Institute National Agronomique (National Institute of Agronomy), where he was an outstanding student. He also attended Hervé Mangon’s evening course in rural engineering at the Conservatoire National des Arts et Métiers (National Conservatory of Arts and Crafts). (Charles-François Hervé Mangon (1821–1888) had been trained as a civil engineer, but his interest shifted to agriculture, where he studied irrigation, drainage, fertilizers, etc.) Ringelmann also attended courses at the École Nationale des Ponts et Chaussées (National School of Bridges and Roads), a civil engineering school. By 1883, he was contributing a weekly column to the Journal d’Agriculture Pratique (Journal of Practical Agriculture).

In 1887, Ringelmann was elected to the Académie d'Agriculture, and in the same year, he became professor of mechanics and rural engineering at the École Nationale d’Agriculture in Grignon. In 1897, he succeeded his former professor Hervé Mangon as professor of rural engineering at the Institute National Agronomique. He became in 1902 professor of colonial rural engineering at the École Nationale Supérieure d’Agriculture Coloniale in Nogent-sur-Marne. In the United States, local ordinances in many cities were passed to prohibit smoke of greater than 3 (60% opacity) on the Ringelmann scale.

Although these charts are still used informally, especially for educational purposes, they are largely obsolete. They are of little use for measuring modern, essentially invisible forms of urban air pollution and have effectively been replaced by more accurate, quantitative methods. In the same way, modern emissions standards (such as the World Health Organization's air pollution guidelines and the US Environmental Protection Agency's Air Quality Standards) refer not to Ringelmann chart values, as they might once have done, but to the maximum allowed or recommended concentrations of different pollutants in the air.

History of Rural Engineering During 1900-1905, Ringelmann wrote a monumental, four-volume study Essai sur l’Histoire du Génie Rural (Essay on the History of Rural Engineering), which traced the progress of rural engineering from pre-history to the modern age. Specifically, Ringelmann had his students, individually and in groups, pull on a rope. He noticed that the effort exerted by a group was less than the sum of the efforts exerted by the students acting individually.

Max Ringelmann died in Paris on 2 May 1931.