The Role of the Societas Meteorologica Palatina (1781–1792) in the History of Auroral Research

Abstract

The Societas Meteorologica Palatina, or Meteorological Society of Mannheim, was set up in 1781 to coordinate observations of the weather on an international scale. In addition to temperature, pressure and humidity, observers connected to the network were instructed to record various atmospheric phenomena, among these the aurora borealis. The 39 stations of the network reported about 1400 individual sightings of auroras during the Society's dozen years of existence. The reported sightings are subjected to a statistical analysis that brings out striking discrepancies between the number of auroras that one would expect and the number that was reported. The statistical analysis is supplemented by an analysis of the theoretical and phenomenological comments in the Society's annual reports. The study suggests that observers on the Continent considered themselves just as advantageously situated as observers further north when trying to solve the riddle of the northern lights. It also illustrates the variety of conflicting ideas about the aurora borealis that existed during the late Enlightenment, and how these might have influenced the number of reported auroras. This lack of consensus contributed to many anomalies in the data presented in the Society's reports. By combining linguistic and scientific competence it is possible to shed light on these anomalies and on the historical context that shaped them.

Keywords:

• Aurora Borealis
• Meteorology
• History of Science
• Eighteenth Century
• Scientific Societies
• Mannheim

Notes

1. Eph. Met. Anni 1783 (1785): 55: “Candor ingens post solis occasum horizonti in N W insidebat” (translated by the authors).

2. In a recent publication, Dalin et al. (2012) have argued that the eruption of Laki 1783 is likely to have produced noctilucent clouds. However, they have no reference to the reports of the Mannheim Society and do not discuss the aurora borealis as a likely source of confusion.

3. “Hora 8¾ aurora borealis usque ad Zenith elata, extensa a cauro usque ad Euro-Boream, parum durat. Acus magnetica signat interim 15°,12 circiter; prius signabat 15°,20” (translated by the authors).

4. “Vesp. h. 9 AB rubens & flavescens sine radiis, nunc praeter alias obscuriores nubes quasi columna nubis in N, ad dextram rub. & flav., ad laevam tantum flav. Hora 10 adhuc inter nubes lumen transparet. Hora 10¼ imber” (translated by the authors).

5. Eph. Met. Anni 1786 (1788): VI: “Egregia plane observatio est, quam Patavii cl. sodales nostri fecerunt, auroram borealem in coelo & coruscationes eodem tempore emicuisse. Utramque hanc lucem continenti successione ex eadem nube prodiisse, & nobis Manheimii ter observatum est, uti in proximo volumine dicemus. Ex quo phaenomeno non leve momentum ei opinioni accedit, quae auroras boreales effectum electricum esse contendit” (translated by the authors).