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Centre for the Study of Manuscript Cultures (CSMC)

06/2014 manuscript  of the month

When Mars is in the sign of Capricorn...

When planning a trip or a barbecue nowadays, one would probably watch the weather forecast on TV, check the weather on the internet or see what an app says. But whoever would have thought of consulting the stars at night? As it happens, up to the 18th century, few people would have denied the connection between the constellations of the stars and the weather on Earth. This superstition, referred to as astro-meteorology, found its expression in the German Schreibkalender (‘writing calendar’), which provided prophecies on the weather for the coming year. A special copy of such a calendar can be found in the manuscript department of the Landes- und Murhardschen Bibliothek in Kassel under the signature ‘Ms. Hass. 4°57’.

Fig. 1:Letter from Hermann IV of Hesse-
Rotenburg from 1 January 1625 (fol. Ir)
> Enlarge

In the winter of 1624, the 17-year-old landgrave Hermann IV of Hesse-Rotenburg (1607–1658) wrote an astronomical and meteorological Schreibkalender at Plesse Castle near Göttingen as a gift for his father, landgrave Moritz “der Gelehrte” (the scholar) of Hesse-Kassel (1572–1632). While a crippled foot forced him to wear an iron prosthesis throughout his life and prevented him from pursuing a military career, it was in science that Hermann's strengths came to the fore. Like his father Moritz and his grandfather Wilhelm IV (1532–1592) – both great patrons of natural science – he was fond of astronomy and was a recognised scholar in the fields of meteorology, mathematics, astronomy and geography. One of his most famous works is the Historia meteorologica, in which he published decades of his own systematic weather observations and thereby invalidated various kinds of weather lore on the basis of empirical findings.

Fig. 2:Page with the explanation of the astro-
nomical symbols and further data describing
the year (fol. 1v). Top left: the library stamp
from the 18th century.    > Enlarge

Fig. 3:Title page of the calendar with an
illustration of the lunar and solar eclipses
(fol. 1r).    > Enlarge

The manuscript – which has been in Kassel since at least 1780 – has a ‘small quart’ format, a name derived from the number of leaves per folded sheet resulting from paper manufacturing. In this case, the sheet of paper was folded twice and formed four leaves. Around 1975, the former cover was replaced by a half-leather binding during restoration and was integrated at the back. This fragment was identified as a medieval manuscript – a 14th-century missal, in fact. A letter in a fine cursive script that Hermann wrote to his father is also included (fig. 1). Unlike the calendar with which it is associated, the letter is written in Latin. It is dated 1 January 1625 and apparently was written at Plesse Castle. After reporting on the well-being of his mother and siblings, Hermann sent his father his best wishes for the coming year and gave him the manuscript – “the first results of my nightly astrological work” – as a present.

The manuscript also reflects modern library history: the stamp “Murhard’sche /Bibliothek der/Stadt Kassel und/Landesbibliothek” is visible on the back of the letter in indelible blue ink. During the period when this stamp was in use (1958–1975), the State Library was under municipal administration, but the manuscript, as the stamp suggests, was not actually “municipal property”. A stamp with the words “EX BIBLIOTHECA CASSELLANA” (fig. 2), however, is to be found on another page that was inserted in the 18th century and explicitly marks the calendar as being the Library’s property.

The following 42 pages include the Schreibkalender, which possesses the usual design features of calendars made in the 17th century. After the actual calendar containing practically blank pages for notes there follows an explanatory Praktik – a common term for ‘commentary’ at the time – which basically summarises the previous content, but has a different focus.

Fig. 4: Graphical illustration of the positions of
astronomical objects (fol. 2r)    > Enlarge

Fig. 5: Page of the calendar for February 1625
(fol. 3v)    > Enlarge

Besides stating the name of the author, the title page – which has a jewellery frame around it (fig. 3) – contains another special feature: four pictures, viz. two blackened suns and partially black moons with astrological symbols attached to them. An explanation follows on the next page – they show the expected solar and lunar eclipses for the year 1625 and the position of the moon in the zodiac on those particular days. Data of this kind was of fundamental importance for any astrological and astro-meteorological considerations.

On the following page (fig. 2) one finds further information describing the year in addition to the explanation of the astronomical signs. There is the “sun’s circle”, for example – a 28-year cycle during which the weekdays occur on the same days of the month in all the years marked by the same number. This information was particular important in calculating the date of Easter. The page after this (fig. 4) is almost entirely taken up by a drawing; the illustration shows the course of the planets on four days with astrological/astronomical significance: the spring and autumn equinox and summer and winter solstice.

Compared to this, the actual calendar is quite simple: in several columns one finds the days of the month, the daily saint, the course of the moon through the zodiac, the expected constellations of stars and finally – in a very brief description – the weather to be expected. On 16 February (fig. 5), for example, Hermann expected Mars to be in the sign of Capricorn, which would mean frost. Other writing calendars of the time offered much more information: not only weather forecasts, but also auspicious dates for marriage, trading, venesection and even getting a haircut. The pages opposite the calendar entries contain space for making notes.

The Praktik can be found after the calendar and consists of three chapters. The first one deals briefly with the Gewitter (nowadays a thunderstorm in German, but back then simply the word for ‘weather’) for each month of the year, the second deals with the weather during the individual seasons and, finally, the last chapter is about lunar and solar eclipses. At the end of this work, Hermann concluded with the wish that the reader might have a happy new year and fare well. Moritz obviously did not use the calendar himself – that is why it still exists and can be used as a source of cultural history and history of science today.


AUFGEBAUER, Peter (2000): ”Die Burg Plesse in hessischer Zeit (1571-1660) nach den Schriftquellen”. In: Thomas Moritz (ed.): Ein feste Burg - die Plesse. Interdisziplinäre Burgenforschung, Vol. 1. Göttingen: Goltze, 99-111.

GROTEFEND, Hermann 14(2007): Taschenbuch der Zeitrechnung des deutschen Mittelalters und der Neuzeit. Hannover: Hahnsche Buchhandlung.

GLASER; Rüdiger (2001): Klimageschichte Mitteleuropas. 1000 Jahre Wetter, Klima, Katastrophen. Darmstadt: Primus.

HERRMANN, Joachim 15(2005): dtv-Atlas Astronomie. München: DTV.

LENKE, Walter (1960): “Klimadaten von 1621-1650 nach Beobachtungen des Landgrafen IV. von Hessen (Uranophilus Cyriandrus)”. In: Berichte des Deutschen Wetterdienstes, No.63, Vol. 9.

MATTHÄUS, Klaus (1968): “Zur Geschichte des Nürnberger Kalenderwesens. Die Entwicklung der in Nürnberg gedruckten Jahreskalender in Buchform”. In: Archiv für Geschichte des Buchwesens LXIV, 735-831.

Id. (1968): “Zur Geschichte des Nürnberger Kalenderwesens. Die Entwicklung der in Nürnberg gedruckten Jahreskalender in Buchform”. In: Archiv für Geschichte des Buchwesens LXV, 1086-1206.

MAHLBERG, Horst (2007): Meteorologie und Klimatologie. Eine Einführung. Berlin: Springer.

WALTHER, Gerrit (2004): “Fürsten, Höfe und Naturwissenschaften in der Frühen Neuzeit. Versuch einer Systematik”. In: Barbara Mahlmann-Bauer (ed.): Schientiae et artes I. Die Vermittlung alten und neuen Wissens in Literatur, Kunst und Musik. Wiesbaden: Harrassowitz, 143-160.

Landesbibliothek und Murhardsche Bibliothek, Kassel, Germany
Shelf mark: 4°Ms. Hass. 57
Material: paper (half-leather binding) (II+33 pages; 1r–21v inscribed)
Dimensions: 19 × 15 cm
Origin: Plesse Castle (landgraviate of Hesse-Kassel), 1624/25

Text by Arne Ulrich
© for all images: Universitätsbibliothek Kassel.