Instrumental Measurements

Late eighteenth century barometers. Source: Science Museum London / Science & Society Picture Library.

Barometers, engraved plate by C. Haushard from "Memoires sur la Meteorologie" (1788) by the Father Louis Cotte (1740-1815). Cotte, Canon of the Cathedral of Laon and a man of scientific letters, was linked, amongst others, with the Académie des Sciences in Paris and the Meteorological Society of the Palatinate in Mannheim (Rhineland-Palatinate), which had established a large international meteorological network for weather measurements. His Mémoires are very well illustrated with the best equipment of his day. Barometers were found in better-off households from the early eighteenth century.

Mercury-in-glass thermometer with Celsius Scale, about 1790. Source: Science Museum London / Science & Society Picture Library.

This mercury-in-glass thermometer was made by instrument-maker Pierre Casati from Lyon about 1790. This thermometer was one of the first to use the Celsius scale of heat measurement, invented in 1742 by the Swedish astronomer, Anders Celsius (1701-1744). The Celsius, or Centigrade, scale initially placed 0 degrees as water’s boiling point and 100 degrees as its freezing point. In 1743, Jean-Pierre Christin, of the Societé Royale of Lyon, reversed this, making 0 degrees the freezing point and 100 degrees the boiling point. This is noted on the thermometer's scale, which is graduated from -35 to +100 degrees. Thermometers were found in better-off households from the late eighteenth century.

Receptacle for measuring the amount of precipitation used by the Bernese Economic Society, 1760. Source: Description d’un récipient servant à mesurer l’eau de pluie collectée. In: Abhandlungen und Beobachtungen der Ökonomischen Gesellschaft Bern 1761/3 (1761): 685-687 (the illustration is only available in the French version).

The Bern Economic Society had a rain-gauge (pluviometer) built in 1760 for its meteorological network that reduced evaporation losses by conducting the rainwater from the cone-shaped receptacle through a narrow tube into a collection container. It was concluded from a statistical analysis that the quality of historic Bern precipitation measurements is equivalent to present day ones (Pfister 1975). Unlike barometers and thermometers which were produced in substantial quantities and distributed by ambulant merchants, rain-gauges had to be manufactured by artisans. This may be a reason why precipitation was relatively rarely measured prior to the nineteenth century. Moreover, as rain-gauges are exposed to the elements, they were rarely preserved. Usually, they are just known from publications.

The Swiss natural scientist Johann Jakob Scheuchzer (1672-1733), copperplate print. Source: Zurich Central Library, Department of Prints and Drawings / Photo Archive.

In his house in Zurich Niederdorf, Johann Jakob Scheuchzer (1672-1733), physician, natural scientist and polymath, kept the first systematic instrumental measurements in Switzerland from 1708 to 1733 (albeit with some gaps) including air pressure, air temperature and precipitation. Moreover, he kept track of the water level of the Limmat River by reading a water gauge. Scheuchzer published his results in scientific journals such as the Parisian Mémoires de l’Académie des Sciences and the London Philosophical Transactions. He wrote his comments in Latin, which was the scholarly language of the century (Pfister 1999: 27). His principal work, the three-volume "Naturgeschichte des Schweitzerlands" (A Natural History of Switzerland), is accessible also in a digitalized version.

Frédéric Moula (1703-1782) was a mathematician originating from a family of Huguenot refugees. He began an instrumental weather diary in Neuchâtel in which he laid down barometric and thermometric readings three times a day from 1753 to 1782 using a Fahrenheit thermometer. Charles-Guillaume Kopp, a Neuchâtel scientist intended to publish his thermometrical measurements in view of putting out the entire manuscript, but this was never done. Meteorologist Max Schüepp published monthly mean temperatures (Schüepp 1961) which were included in Euro-Climhist (series 12).

Johann Jakob d’Annone, a Basel University lawyer, kept a meteorological diary for 49 years. Source: Basel University Library.

Johann Jakob d’Annone (1728-1804), a lawyer, taught Roman Law, Numismatics, Mathematics and Natural Sciences at the Basel University. 1766 he there got a chair for Eloquence and from 1779 for Roman and Feudal Law. He can be seen as a “representative of the encyclopaedic era” (Andreas Staehelin). Five of his numerous publications deal with meteorology, five more are dedicated to his actual speciality, the fossils (Staehelin 1957: 321). From 1755 until his death he kept an instrumental weather diary in his house Heuberg 16 in Basel. His measurements included the daily reading of a thermometer and a barometer. Bider, Schüepp and von Rudloff (1959) homogenised the temperature series, but it turned out that the reconstructed summer temperatures are still too high (Auer et al. 2007).

The meteorologists from Geneva in the late eighteenth century
As many as four scientists were dealing with atmospheric sciences in Geneva after 1760, whereas the Société des Arts (founded 1776) served as a platform for scholarly exchange (Grenon 2010).

Charles Benjamin, Baron de Lubières (1714-1790), born into a Huguenot refugee family, was a member of the Great Council of Geneva. He daily observed wind direction, cloud cover and stages of vegetation from 1770 to 1789. Moreover, he laid down measurements of air pressure, temperature and precipitation. Lubières lived in Petit Sacconex close to the former town in summer, while he lived at the Rue de Beauregard in Geneva in winter. His observations filed in the archive of the Geneva University Observatory in Sauverny were so far not investigated (Gautier 1843; Häderli 2015). His precipitation record from 1771 to 1777 is of particular value, because it extends the long Geneva precipitation series (from 1778 onwards made by the Geneva Observatory) for seven year (Grenon 2010) (series 9).

Guillaume-Antoine Deluc (1729-1812), a member of the Great Council of his hometown, was a brother of the well-known physicist and geologist Jean-André Deluc. From his youth he had a passion for scientific (mainly meteorological) observations and geology (fossils). Together with his brother he climbed up several peaks of the Mont Blanc massif. Deluc kept an instrumental weather diary from 1768 (Gautier 1843: 3), which has been evaluated by Schüepp (1961) and Häderli (2015) (series 7).

Marc-Auguste Pictet (1752-1825) worked as a legal consultant for the Great Council. He addressed himself to the study of physics and meteorology. From 1779 he was in charge of the Geneva Observatory founded in 1773 (Grenon 2010).

The precipitation series of Geneva (1771 to present) being one of the longest in Europe is composed from the measurements made by Lubières (1771 to 1777), from those carried out at the Observatory (1778 to 1863) and those made within the MeteoSwiss network (since 1864). It is for the first time published in Euro-Climhist, but the values are not homogenised before 1864 (Sigrist 1990) (series 9). In 1782, Geneva became a station in the large-scale network of the Societas Meteorologica Palatina founded in 1780. The Senior librarian Jean Senebier (1742-1809) carried out the measurements (Grenon 2010). The Mannheim Society provided standardized meteorological instruments for its stations determining measurement times and publishing the results in a Yearbook.

The water gauge of river Rhine at the pier in Basel. Source: Oliver Wetter, Basel.

The water gauge record of the Rhine River at the pier in Basel – extending back to 1808 – is the longest known, uninterrupted daily discharge series of this kind in Switzerland. It allows discerning situations of extreme floods and low-stage events that were produced by outstanding precipitation or long-term hydrological droughts (Pfister, Weingartner, Luterbacher 2006; Wetter et al. 2011).