Gnomonica Medioevale

The Tall Gnomon (kao piao) of the ancient observatory at Gaocheng , Henan Province, China (34° 24’ 8.73” N, 113° 8’ 26.23” E) is described in a contemporary historical document in terms of  tracking changes solar altitude at meridian transit between summer and winter solstices  (Needham et al.  1954, 296-298; Sivin 2009, 183-186).  For example, the Yuan History (Yuan shih) records that the sun’s shadow cast near the winter solstice on 14 December 1278 AD measured 76.7400 feet (Needham et al. 1959, 299; Mercier 2003, 197-198; Sivin 2009, 571).  However, the 128-foot horizontal graduated template scale (kuei-piao) of the Tall Gnomon is 40% longer than what is required to measure the sun’s longest shadow at the winter solstice.  Using GIS and astro-archaeological computer modeling, additional astronomical targets (i.e., Midsummer Moon,  Venus and bright Stars) are proposed that could account for the construction of the extra 51 feet in length of the template scale.  Evidence is also presented that the solstice observations reported in the Yuan History could not have been made at Gaocheng, but rather at Beijing.

References
Mercier, Raymond.
2003  “Solsticial observations in thirteenth century Beijing.” SCIAMVS,  4:191-232.

Needham, Joseph
1959  Science and Civilization in China, III, London: Cambridge University Press.

Sivin, Nathan
2009  Granting the Seasons:  The Chinese Astronomical Reform of 1280.  New York: Springer.

In medieval Hungary surely many different sundials were in use to indicate the passing time, but for today only a few
remained which can be still studied. There are especially not many of them which came to the light from archaeological
excavations. Therefore, the analysis and the presentation of the fragments of a sundial that was unearthed in the
church of the Benedictine monastery at Kaposszentjakab is, among other reasons, very important. In addition to the
description of this fragmented sundial from Kaposszentjakab, in the article the author also summarizes the knowledge
about sundials in general as well as he presents those wall clocks and pocket watches that were until now revealed
in Hungary. To do so was an essential task, since from the archaeological point of view no one ever provided such a
summary before. Until now mainly the astronomers were interested in sundials, and not so much the historians and/
or the archaeologists.

Sundials in Roman and Byzantine Mosaics (1st – 9th Century AD). A scientific monograph. The sundials on ancient mosaics have not been the subject of scientific studies so far. The author has gathered together  in this  publication  the sundials  already known (Torre Anunzaiata, Sarsina, Trier, Saint-Romain-en-Gal, Antioch and Brading; Figs. 1, 2, 4, 5, 7, 9) and those which have  not  previously  been  identified.  Thanks  to  the author’s  new  identifcations,  the  catalogue  has  been enlarged  by  six  new  sundials (Grand,Tarsus, Antiochia – interpreted by H. Pamir; Figs.  3, 6,  8, and 10. Tayibat al-Imam, Jerusalem and Umm al-Rasas (Sebastis); Figs. 10, 11, 12) and three monumental gnomes-columns with multiple functions that were used as monumental sundials [Madaba (Jerusalem), Umm al-Rasas (Kastron Mefaa) and Rome (Jerusalem); Figs. 13–15]. In addition, recognizing fully John H. Humphrey’s  interpretations,  the  author  enriches  the catalogue  by  eight  ancient  mosaic  representations  of obelisks in  circuses (Lyon, Barcelona, Volubilis, Piazza Armerina - two mosaics, Girona, Carthage and Gafsa; Figs.  16–23).  They  performed the roles of monumental sundials. In this way, the catalogue includes  twenty-three  mosaics with  the representations of sundials. They come from the Western and Eastern Provinces of the Roman Empire. The first mosaic is dated to the beginning of the 1st century AD and the last dates to the 9th century AD. The author, after  a  short  description  of each monument,  summarizes the issue discussing the role of sundials in Roman and Byzantine society, their complex signifcance and symbolic dificult linked with the progress of time on which nature and human life are dependent. See Pdf : https://www.academia.edu/22653583/

"This paper proposes three new (and tentatively, another two) identifications of sundials in Middle Eastern mosaics of the 5th – 8th century. The author discusses a vignette from the Holy Martyrs’ Church at Tayibat al-Imâm, central Syria, a mosaic panel from the tomb of Georgia and Theodosia in Jerusalem, two
vignettes of Sebastis and Kastron Mefaa from the St. Stephan’s Church at Umm al-Rasas, and a vignette of Jerusalem from the St. George’s Church at Madaba. These mosaics date, respectively, to 442, to the reign of Justinian (527 –565), and to the Byzantine Umayyad era (718). According to the author, these are probably the latest representations of sundials known to date from the Late Antiquity. Until this study, only six representations of sundials on mosaics from the Roman period were known. This paper adds three new items and two hypothetical ones from Byzantine times. It also offers an interpretation of the function of the famous column in Jerusalem, shown on the map of Madaba and the mega-vignette of the Holy City.
Key words: Sundials, Sonnenhuhren, Meridiane, Cadrans solaires, Relojes de sol."

first volume of a series devoted to the census of the Italian medieval sundials. This volume explane the history and the origin of medieval sundial in Christian lands. And ivestigates on the many type of sundials in medieval period. This book is written also by many other authors from England to France, from Spain to Israel. It contains also the most complete census nowaday of the medieval Armenian sundials. To purchase the book. please ask to marnaldi@libero.it

Nel numero 16 di Gnomonica Italiana furono illustrati ed elencati da Karlheinz Schaldach gli ‘schemi delle ombre’, riportati in un gran numero di manoscritti medievali latini. L’articolo non aggiunge nulla di nuovo al metodo di suddivisione dei vari modelli descritti in quell'articolo, ma arricchisce l’elenco delle testimonianze manoscritte con nuovi testi recentemente ritrovati dall'autore.
In Gnomonica Italiana n. 16 the 'shadow schemes', reported in a large number of medieval Latin manuscripts, were illustrated and listed by Karlheinz Schaldach. This article does not add anything new to the dividing method of the various models described in that article, but it enriches the list of handwritten testimonies with new texts recently found by the author.

In questa seconda parte dell’articolo l’autore prosegue con le sue considerazioni sulle ore ineguali, focalizzandosi esclusivamente sulla percezione del tempo nel Medio Evo. Sebbene il concetto geometrico e astronomico antico fosse ben chiaro fin dai primi tempi dell’epoca ellenistica, questo, nella pratica già tardo–antica e poi medievale, incominciò a sfuggire di mano anche agli eruditi.

"""A sundial is the most natural, and at the same time the first known instrument invented
and used for measuring time. The authors of this publication take an effort to display the
history of the sundials situated in the city of Toruń. These sundials have never been subjected
to such detailed studies before. It is reasonable to assume that, similarly to the other cities of
the Medieval Europe, sundials were used also in Toruń probably from beginning of XIII
century. Even later, when mechanical tower clocks were installed, the sundials were still
widely used. Their readings served as reference for setting and correcting the mechanical
clocks. Unfortunately, those older sundials of Toruń are not preserved until now. No
information about them has been either found in the literature.
Documented history of the sundials of Toruń starts only in February 1704. Then,
almost five months after the Town Hall belfry with its mechanical clock and bells had been
damaged, a publicly available sundial was installed on the Chełmińska Gate. This sundial was
assigned, as we assume, to function as a temporary metropolitan clock. In 1740, after the
Town Hall had been rebuilt, a big, vertical sundial was installed in the middle window on the
southern elevation of the building. That was probably expected to be the temporary solution to
the problems with readings of the mechanical clock, installed twelve years earlier on the
renovated belfry. Although intended as a provisional project, the sundial installed on the
Town Hall survived about 160 years and was removed only after 1899 and before 1903. The
sundial’s appearance was immortalized by graphics from XVIII century, and in 19th century
photographs. Based on these evidences we may conclude that it was a simple, one-function
sundial. Another sundial in Toruń was only recorded in local ancient legends and popular
tales of the town’s history. It is often mentioned there that Nicolaus Copernicus was supposed
to design, and maybe also to make the sundial on the St. John’s parish church. It is now
impossible to verify this thesis. It is a fact, however, that still in the twentieth century, on one
of the southern buttresses of this church there were yet visible: gnomon and some parts of
plaster – the remains of a dial of a sundial, but possibly a younger one than that ascribed to
Nicolaus Copernicus.
Only two historical sundials are preserved in Toruń until the present time. They both
come from the late XIX century. They are of vertical type and had been designed mainly for
decorative purposes – they were used to ornament buildings. The sundial situated at the top of the
facade of a tenement house on św. Katarzyny 6 Street, manufactured in 1895, is a sort of a memento
after the Town Hall sundial from 1740 – and was probably modeled after it. The second sundial,
integrated with the timber-framing elevation from 1899 of a villa on Konopnicka 16 Street, is
unfortunately broken. The next sundials in the public area of Toruń appeared in the late 1960s and
early 1970s. Their main purpose was to commemorate the 500th birthday of Nicolaus Copernicus.
Some of them are interesting, as they display riveting astronomic ideas. They also, through their
artistic concept, demonstrate some general outlooks.
The whole publication is in Polish."""

The second volume of the serie “Tempus et Regula”, devoted to the census and to the study of the medieval sundials in Italy, lists more than 55 medieval sundials found in Sardegna till nowaday. To every sundial is written a technical and historical record, for the most interesting one is deserved a monograph study. A simple but rigorous language, makes the volume accessible to all sundials friends and to all people courious of history of scences.

Il secondo volume della serie “Tempus et Regula”, dedicata al censimento e allo studio degli orologi solari medievali italiani, elenca più di cinquantacinque orologi solari medievali trovati in Sardegna fino ad oggi. Ad ogni orologio solare è dedicata una scheda tecnica e storica, mentre a quelli più interessanti è riservato uno studio monografico. Questo volume, come tutti quelli della serie “Tempus et Regula”, vuole essere uno strumento utile allo studio nonché alla tutela del patrimonio gnomonico medievale italiano, cui gli enti giuridicamente preposti potranno attingere al fine di proteggere da cattivi e infausti restauri i pochi resti di cultura ‘scientifica’ medievale che le pietre erose dal tempo sono in grado di testimoniare. Un linguaggio semplice, sebbene rigoroso, rende il volume accessibile a tutti gli appassionati di orologi solari e ai lettori curiosi delle scienze antiche.

This volume of Tempus et Regula is the third of a more complex work dedicated to the census and the study of medieval Italian sundials. This book lists and studies all the medieval sundials found by the author in the Marche and Umbria regions. A technical and historical data-sheet is dedicated to each sundial, while a separate monographic study is reserved for the more interesting ones. To frame the development and characteristics of these tools, various topics related to them have been examined, such as civilization, religion and the times of prayer. This volume, like all those in the "Tempus et Regula" series, is intended to be a useful tool for the study and protection of the Italian medieval gnomonic heritage, which the juridically responsible bodies can draw on in order to protect the few remains of medieval "scientific" culture that the stones eroded by time are still able to testify. A simple, though rigorous, language makes the text accessible to all sundial enthusiasts and curious readers of the ancient sciences. News and new gnomonic discoveries offer to the scholar new ideas for an investigation that from now on cannot be left out.

Questo volume di Tempus et Regula è il terzo di un’opera più complessa dedicata al censimento e allo studio degli orologi solari medievali italiani. In questo libro sono elencati e studiati tutti gli orologi solari medievali trovati dall’autore nelle regioni Marche e Umbria. Ad ogni orologio solare è dedicata una scheda tecnica e storica, mentre a quelli più interessanti è riservato uno studio monografico a parte. Per inquadrare lo sviluppo e le caratteristiche di questi strumenti sono stati presi in esame diversi argomenti ad essi collegati, come la civiltà, la religione e i tempi della preghiera. Questo volume, come tutti quelli della serie “Tempus et Regula”, vuole essere uno strumento utile allo studio nonché alla tutela del patrimonio gnomonico medievale italiano, cui gli enti giuridicamente preposti potranno attingere al fine di proteggere da cattivi e infausti restauri i pochi resti di cultura "scientifica" medievale che le pietre erose dal tempo sono ancora in grado di testimoniare. Un linguaggio semplice, sebbene rigoroso, rende il testo accessibile a tutti gli appassionati di orologi solari e ai lettori curiosi delle scienze antiche. Novità e nuove scoperte gnomoniche offrono allo studioso nuovi spunti di investigazione che d'ora in poi non potranno essere tralasciati.

"Les informations concernant les cadrans solaires de l’Antiquité proviennent de sources multiples: archéologiques, littéraires, épigraphiques et iconographiques. La mosaïque est notamment une source importante permettant de les appréhender dans leur véritable contexte.
Jusque très récemment, le nombre de représentations de cadrans solaires identifiés sur les mosaïques antiques était limité à six cas, tous - à l'exception d'un pavement, de l’époque romaine et situés dans les provinces occidentales du Ier s. av. J.-C au IIIe s.: Torra Annunziata (à côté de Pompéi) et Sarsin (Ombrie, Italie), Broading sur l’Île de White (Grande-Bretagne), Trèves en Germanie, Saint Romain-en-Gal en Gaule et Antioche en Syrie (aujourd'hui en Turquie). Désormais, grâce à de nouvelles identifications, notre catalogue vient de doubler.
Les six mosaïques avec représentation de cadrans solaires identifiés récemment proviennent du Proche-Orient et sont datées du Ve au VIIIe siècle, à l’exception d’une, gauloise, trouvée dans une basilique publique (?) à Grand (IIIe s.). Les cinq mosaïques proche-orientales proviennent des provinces de Syrie Seconde, d’Arabie et de Palestine Première et pavaient des basiliques chrétiennes: Tayyibat al-Imam, Umm al-Rasas (vignette de Sebastis et de Kastron Mefaa), Madaba (vignette de Jérusalem); celle de Jérusalem ornait le sol d’une chapelle funéraire ou d’une tombe.
Key words: Sundials, Sonnenhuhren, Meridiane, Cadrans solaires, Relojes de sol
See: M.T. Olszewski, Cadrans solaires sur trois mosaïques byzantines au Proche-Orient et quelques autres identifications hypothétiques de gnomons géants, Archeologia (Varsovie) 60, 2009 (2012), p. 69-79, pls. IX-XI.
M.T. Olszewski, Les cadrans solaires dans les mosaïques romaines et byzantines (Ier siècle ap. J.-C. - IXe siècle ap. J.-C.), [in:] A. Tomas (ed.), Ad fines imperii Romani. Studia Thaddaeo Sarnowski ..., Warszawa 2015, pp. 449-468
https://www.academia.edu/19421274

La facciata della Cattedrale di Matera presenta numerose asimmetrie. Alcune sono così evidenti che risaltano anche a occhio nudo. Altre invece sono meno vistose e solo con attenzione si riesce a scrutarle. Sia perché -erroneamente- ritenute marginali e irrilevanti, sia per la scarsità di studi sull’argomento...

Questo contributo espone i punti fondamentali di un metodo di ricerca messo a punto con l’aiuto di numerosi casi-studio riguardanti l’architettura sacra di età medievale.
Nel rapporto tra Architettura e Spazio Celeste, che con i suoi elementi e il loro reciproco movimento ha segnato la storia dell’umanità, è possibile individuare tre diverse problematiche progettuali.
La prima concerne l’allineamento dei corpi di fabbrica con punti dell’orizzonte visibile segnati in date particolari dell’anno astronomico, o dell’anno liturgico per gli spazi sacri, dalla levata o dal tramonto di un corpo celeste quali sole, pianeti, stelle o luna.
La seconda riguarda il rapporto che intercorre tra la progettazione planimetrica e quella degli alzati.
Il terzo ambito di studio, a differenza dei primi due, è collocabile a valle dell’attività progettuale ed edificatoria e concerne la distribuzione dell’apparato decorativo in relazione alla luce naturale

L’edificazione della Cattedrale materana in forme romaniche avvenne in epoca tarda, verosimilmente dal 1230 circa al 1270 e nel corso dei secoli la facciata principale,
orientata a Ovest, è divenuta l’icona della città storica, anche per la sua posizione predominante e a favore dei punti più panoramici.
Il nostro interesse però, oggi si concentra sul fianco meridionale del monumento, sul quale si rinviene un gran numero di attestazioni graffite, che si rivelano testimonianze
utili alla comprensione di una serie di dinamiche storiche che agli occhi moderni possono inizialmente sfuggire. Diventando tali segni sempre più flebili, anche a seguito di ogni pulitura, è bene fissare quanti più dati del loro vissuto.