Eurodials – GAUDIUM SUB SOLE . SUNDIALS . MEDIEVAL TO MODERN

BASILICA di SANTA MARIA NOVELLA . FLORENCE – MERIDIAN DIAL

Published on March 13, 2023 by Rolling HarbourLeave a comment

Santa Maria Novella, one of the most sublime churches in Tuscany, needs no general introduction. The Wiki article SMV gives a very good overview. The focus of this article is on the amazing meridian dial inside the church itself.

First, I should mention the 2 famous dials on the facade, the subject of much interest, investigation, and analysis including detailed articles by BSS. I plan to feature both separately in due course. On the left is an armillary sphere; on the right is an astronomical quadrant. They are the work of Egnatzio Danti, astronomer to Cosimo I, and were installed c1570.

*Armillary Sphere & Astronomical Quadrant on the Facade (Egnazio Danti c1570)* *cc os*

The Museo Galileo has a comprehensive website here MG and is a superb resource for historical science. Exhibits include 2 of Galileo’s telescopes. In 2007 it held a remarkable dial-based exhibition called The Line of the Sun. The entry for SMN includes all 3 dials and gives a succinct account of their creation and significance. I am adapting / adopting some entries from the museum’s explanations.

MERIDIAN DIAL

Background: Between 1572 and 1575, the cosmographer Egnazio Danti (1536-1586) installed on the façade of Santa Maria Novella no less than three astronomical instruments: a great quadrant with sundials; an equinoctial armillary; and two ‘camera obscura gnomons’. These instruments were designed to be used for new astronomical calculations linked to the project for reforming the Julian calendar…

Meridian Dial: Although Danti designed the dials he was unable to complete the tracing of the meridian line on the floor of the church. He only opened gnomonic holes, first in the glass of the rose window, then on the church’s façade, much higher, and made two openings in the vaulting as well, through which rays of light would pass only during the equinoxes and the winter solstice.

Operation: The entrance of the sunbeam was through the two gnomonic holes. The pinhole on the rose-window would have allowed [the measurement of] time during the entire year. The pinhole on the façade would have allowed the same reading only in the days of the equinoxes and of the winter solstice (IMSS Multimedia Laboratory).

FACADE POSITIONS

Gnomon holes on the facade in the rose window (70′ high) and just below the pediment

MERIDIAN DIAL IN DETAIL

Basilica of Santa Maria Novella . Firenze . Meridian Dial – Keith Salvesen

REFERENCES / CREDITS

MUSEO GALILEO

Wiki cc – header image / close-up

‘photo tsettle’ – gnomon hole positions

All dial photos – Keith Salvesen

MUSEUM VAN LOON . KEIZERSGRACHT . AMSTERDAM – 3 Sundials

Published on February 1, 2023February 3, 2023 by Rolling HarbourLeave a comment

The attractive gardens of the Van Loon Museum contains 3 very different dials. In the centre is an armillary sphere (C19?). By the steps is a complicated early scaphe dial dated 1582. I have included B&W images, which can sometimes be useful for seeing details on multiple dials. The third dial with a weather vane is high up in the centre of the upper gallery overlooking the garden. I am trying to find out a date for it.

ARMILLARY SPHERE

SCAPHE DIAL 1578

VERTICAL DIAL AND WEATHER VANE

This image has an empty alt attribute; its file name is museum-van-loon-amsterdam-sundials_3136-2.jpg

GSS Categories: Armillary Sphere; Cube Dial; Multi Dial; Scaphe Dial; Modern Dial; Amsterdam Dial

All photos: Keith Salvesen

MONUMENTAL SUNDIAL . MUSEO GALILEO . FLORENCE

Published on October 18, 2022October 22, 2022 by Rolling HarbourLeave a comment

Lizard / Viper Gnomon of Monumental Dial . Museo Galileo . Florence

MONUMENTAL SUNDIAL . MUSEO GALILEO . FLORENCE

The Museo Galileo‘s Monumental Sundial was built as a mathematical ornament in 2007. The slender bronze column (stele) is in fact formed from two matching columns closely aligned, symbolising day and night. The (mid)day stele faces south, with a vertical meridian line on which the shadow is cast by a lizard’s tail (actually, an imaginary half-lizard, half-viper). The night stele faces north and signifies the constellations Ursa Major and Ursa Minor that enable the Pole Star to be identified.

Monumental Dial . Museo Galileo . Florence

The encircled quadrant design on the pavement at the base of the bronze columns indicates the geographic orientation. This glass base of the gnomon, and also the Zodiac signs in the meridian line (below), are up-lit after dark.

Orientation dial . Monumental Dial . Museo Galileo . Florence

The Museo explains the meridian line in helpfully simple terms: A travertine and brass meridian line is drawn on the pavement, flanked with glass and marble signs of the Zodiac. The meridian line extends for about 15 metres from the museum entrance, where the winter solstice is marked, to the base of the gnomon, where the summer solstice is marked. The travertine curves crossing the meridian line indicate the date. The brass radial lines forming a grid with the two solstitial curves indicate the hours.

The seasons and the four elements are symbolised by the choice of materials: travertine for the earth and autumn; glass for the water and winter; grey stone for the air and spring; bronze for the fire and summer.

LIZARD / VIPER GNOMON ON THE SOUTH FACE OF THE COLUMN

This extraordinary sundial stands by the Arno with the Ponte Vecchio (which itself has a wonderful dial LINK) close by to the west. For anyone with even a minuscule interest in or curiosity about the gradual development of scientific instruments and techniques from medieval times onwards, pay a visit to the excellent online gallery LINK. Look in particular for the two astronomical telescopes made by Galileo himself.

The North American Sundial Society has very good online information about this unique dial. You can watch a short animation of how this gnomonic sundial works here LINK

For those interested in finer details of the way the dial works, the museum’s detailed account is included at the end of this article.

Museo Galileo – Istituto e Museo di Storia della Scienza

Museo Galileo – Monumental Sundial

NASS (North American Sundial Society) Video: Filippo Camerota, Luise Schnabel, Giorgio Strano

How the Sundial works

The shadow cast by the glass polyhedron atop the large bronze gnomon indicates the date and time. The hours from 9:00 AM to 2:00 PM are marked out by radial brass lines. The date is indicated by the travertine traversal lines which mark the Sun’s diurnal course for various periods of the year – precisely when the Star enters the signs of the Zodiac. The shadow cast by the gnomon changes in length during the course of the days and seasons, and indicates true solar time for the place where it is located, which is a different time than that of our wristwatches, known as mean time. In respect to mean time, true solar time has a periodic variation that can exceed a quarter of an hour.

Moreover, during daylight saving time, the hands of a clock are moved forward one hour. For example, true midday in the month of February would be indicated by the sundial around 12:28 AM while in the month of July it would be indicated around 1:20 PM daylight saving time.

To read the hour and date, you have to identify the hour lines and the calendrical lines closest to the gnomon’s shadow. When the shadow does not fall exactly on a hour line, you can read the half-hours and quarters with close approximation by ideally subdividing the space between two hour lines in two or four parts. The date can also be read by referring to the Zodiac signs and the start of the months marked out along the meridian line.

© 2018 – 2022 Museo Galileo – Istituto e Museo di Storia della Scienza
Piazza dei Giudici 1 · 50122 Firenze · ITALIA
tel. +39 055 265 311 – P.I. 01346820481

LLUC MONASTERY . MALLORCA . COMPLEX MULTI-DIAL: from Canonical to 20th Century

Published on July 17, 2022July 18, 2022 by Rolling HarbourLeave a comment

Multiple Vertical Sundial, Lluc Monastery, Mallorca (Keith Salvesen) — Lluc Monastery . Mallorca – Sundial (Keith Salvesen)

The secluded Monastery of Lluc is situated near Escorca in the Tramuntana mountains of Mallorca. It dates from the c13, and is famous for its Black Madonna, the discovery of which is said to have led to the monastery’s foundation . It is a place of pilgrimage. The location is remote and peaceful, though inevitably the monastery has become an essential stop on the tourist and coach party trail. We returned there recently, not having visited Mallorca for more than 20 years. The buildings were much as we remembered, but the parking and visitor arrangements were more regimented and complex. Before, one just drove down the narrow road from the main mountain road and parked in the forecourt area close to the buildings. Now, everything is (unsurprisingly) geared to a daily mass influx of people and their needs for sustenance and souvenirs. We were pleased to see that it is still possible to stay at Lluc in one of small rooms under a long covered walk where the monks once slept. You can even book a room for the night.

A short walk from the monastery, there is a path that leads up to a calvary and some great views. Along the way is an amazing multiple vertical sundial. It was designed by Rafael Soler, and carved in 1991. It displays with some style the evolution of sundials from medieval to modern. There are two historical dials, one solar dial, and two seasonal dials.

CANONICAL HOURS – LATINATE

This dial simply records the 3-hourly canonical divisions of the liturgical day (as with the early medieval mass / scratch dials), starting with midnight (top) and working counterclockwise round a central gnomon.

Lluc Monastery . Mallorca – Sundial (Canonical)

CANONICAL HOURS – BABYLONIAN / MALLORQUIN

A more complex dial, starting at noon shown as XXIV (I’m not clear why not XII) through to 21.00. The dial includes months and the signs of the Zodiac.

Lluc Monastery . Mallorca – Sundial – Babylonian / Mallorquines

TEMPS VERTADER – TRUE SOLAR TIME

The centre dial shows true solar time. The polar gnomon (triangular) shows the hours, the pointer shows the date with the declination lines. The inscription MULIER AMICTER SOLE (Woman Clothed by the Sun) references an account in the Book of Revelations. You can find out more HERE

MEAN TIME DIAL (SUMMER /AUTUMN)

The two right-hand sundials are complementary and each covers two seasons. Presumably for a particular month, one dial will be reliable as to time and the ‘off-season’ one will not. The words are Catalan eg Hores Mitjanes = Mean Time; Estiu I Tardor = Summer and Autumn.

MEAN TIME DIAL (WINTER / SPRING)

The creation of these dials was obviously a labour of love and skill combined. There’s doubtless plenty more to be said about these sundials and the splendid ensemble but I decided not to get too technical – indeed, as an amateur I don’t understand enough to do so. The rather washed out appearance of the images was operator error – I had the camera on the wrong settings and didn’t realise until too late…

GSS Category: canonical to modern multi-dial; sundial Lluc Mallorca

All photos: Keith Salvesen; snippet from BSS record

Original Credits: ‘Props to arby101ca and lumbricus, members of a geocaching & waymarking website called Groundspeak. They hiked to Lluc (respect!) and wrote informatively about these dials. I found relatively little elsewhere.

HAUTRIVE . ORNE . NORMANDY . ÉGLISE SAINT-MARTIN – Scratch Dial

Published on July 2, 2022 by Rolling HarbourLeave a comment

ST MARTIN . HAUTERIVE . ORNE . NORMANDY

This unassuming little village is about 10 kms NE of Alençon, in the lower part of an area of Normandy south of Caen where medieval dials can be found on a number of village churches. Mostly, they are single examples but a handful of churches have a profusion of dials that are quite hard even to count let alone analyse.

DIAL

The dial is quite complex. Its position is on the quoin of the chancel, however the only reference I have found suggests it was at one time on the R side of the main doorway. The church is obviously well looked-after and its care may have involved relocation of stones when repairs were carried out.

The details of the dial’s semicircular design are intricate. There is a big blocked gnomon hole that must have been enlarged over the years from something more proportionate. The noon line is emphasised by a large terminal pock. 10± visible lines radiate from the centre, though there must have been more. Most end in pocks: some single, some double, some triple. The pocks themselves have small lines around them, or 2 are joined to each other. Overall, the impression is of a perfectly serviceable traditional Mass dial that has been made enjoyably decorative.

I have included close-ups of the lower quadrants of the dial together with side shots to better show the complexity of the dial in its eroded state. I have never encountered one quite like this.

GSS Category: Scratch Dial; Mass Dial; Medieval Dial France

All photos: Keith Salvesen

ST RÉMY DU VAL . SARTHE . NORMANDY . FRANCE – St Rémy et St Rigomer

Published on May 1, 2022May 5, 2022 by Rolling HarbourLeave a comment

St Rémy et St Rigomer . St Rémy du Val . Normandy

St Rémy du Val is about 12m SE of Alençon, in a countryside of fields and forests. The church of St Rémy et St Rigomer stands high above the river Bienne, beside a now-ruined small castle. It has early origins but dates mainly from C15. The strong tower also had a defensive purpose. At some stage a small and attractive renaissance double doorway was added, a pleasing architectural contrast.

DIAL

The dial is located on the SW face of the buttress shown in the foreground of the header image. There is a definite tilt to this part of the church supported by the buttress, and to the adjacent buildings (the photo exaggerates it considerably).

I wasn’t expecting to find a dial (or even looking for one), and I was lucky to see such an unobtrusive example as we walked past. I later discovered that there is one other mention of it, and of a possible small dial close to it.

*St Rémy et St Rigomer . St Rémy du Val . Normandy – Scratch Dial Gallery*

The dial is considerably eroded and quite badly damaged in the lower R quadrant. Close-to, its relative sophistication is evident. The radials are within a double circle and as far as one can tell do not overlap the inner circumference. Almost certainly the lines were incised all the way round the gnomon hole. There is a hint that in the lower half – or perhaps just the lower L quadrant – there are half-hour marks as well. Perhaps these details suggest a C16 dial.

St Rémy et St Rigomer . St Rémy du Val . Normandy – scratch dial (detail)

SMALL DIAL?

Michael Lalos, who runs a very good site for French sundials of all types, also found this small design. At first sight it doesn’t look very promising as a dial, and might perhaps be an apotropaic symbol. However in the last year I have found 2 or 3 very similar designs that in their context were most likely intended as dials.

GSS Category: Scratch Dial

All photos Keith Salvesen except the last pair, Michael Lalos

BARFLEUR . FRANCE . Saint-Nicolas – Vertical Dial

Published on April 8, 2022 by Rolling HarbourLeave a comment

Barfleur is a small town / large village on the NE tip of the Contentin peninsula in Normandy, roughly due E of Cherbourg. The church of St Nicolas, despite the initial impression, was built mid-C17. Later additions and restoration mid-C19 incorporated an impressively large sundial (it doesn’t seem to have been a later addition).

The face of the dial has almost entirely been obliterated, with half a dozen very faint lines just visible in the lower L quadrant. There is also the hint of a frame under the cast shadow, though it might simply be the remains of a horizontal line. Erosion by the sea over many decades has made the details speculative. The gnomon may possibly be original. Whether or not, the design of the tip is clever and includes a small hole at the tip that creates a neat spearhead.

GSS Category: Old Dial; Eurodial; French Sundial

All photos: Keith Salvesen

LAVAUDIEU . AUVERGNE . MAIRIE – Dial Simplicity

Published on April 5, 2022 by Rolling HarbourLeave a comment

Lavaudieu is a small Auvergne town with a fine romanesque Abbey. For present purposes, the sundial on the wall of the Mairie is the attraction. On a bright sunny day, the simplicity and legibility of this civic dial is hard to beat. The ‘arrowheads’ might be considered a little too ornate for the overall design.

‘Moins est plus’ might be a good motto for the dial, as it is more generally. As soon as I saw it I knew it would be in my top 20 non-medieval dials. It still is.

GSS Category: Modern Dial

Photos: Keith Salvesen

LES CADRANS SOLAIRES DE COARAZE: CERAMIC TILE SUNDIALS IN PROVENCE

Published on December 27, 2021December 27, 2021 by Rolling HarbourLeave a comment

Cadrans Solaires Sundials Coaraze (© Keith Salvesen) — Cadrans Solaires . Ceramic Sundials . Coaraze . Provence – Jean Cocteau

LES CADRANS SOLAIRES: THE CERAMIC TILE SUNDIALS OF COARAZE, PROVENCE

The nine sundials shown below are in Coaraze, a small medieval ‘village perché’ (650m) in the Alpes-Maritimes, Provence, north of Nice. They include sundials by artistic polymath Jean Cocteau (poet, novelist, dramatist, designer, artist and filmmaker); Ponce de Leon; and Henri Goetz, among others. They are located in two places in the village (1) on the front and side walls of the Marie (2) at the top of the village on a south-facing walls in the square in front of the church. They need no interpretation by me: everyone who views these wonderful sundials will experience their own personal response to each one.

MONA CRISTIE – LA CHEVAUCHÉE DU TEMPS

Cadrans Solaires . Ceramic Sundials . Coaraze . Provence – Mona Cristie

GEORGES DOUKING – LES ANIMAUX FABULEUX

Cadrans Solaires . Ceramic Sundials . Coaraze . Provence – Georges Douking

JEAN COCTEAU – LES LÉZARDS

Lizards are the historic symbol of the village

coaraze-sundial-3b.jpg (1280×960) — Cadrans Solaires . Ceramic Sundials . Coaraze . Provence – Jean Cocteau

GILBERT VALENTIN – LES TOURNESOLS

coaraze-sundial-4a.jpg (1280×960) — Cadrans Solaires . Ceramic Sundials . Coaraze . Provence – Gilbert Valentin

FABIENNE BARRE (2008)

On the side wall of the Marie, with a view of the village

coaraze-sundial-5a.jpg (1280×1049) — Cadrans Solaires . Ceramic Sundials . Coaraze . Provence – Fabienne Barre

coaraze-sundial-5c.jpg (1280×963) — Cadrans Solaires . Ceramic Sundials . Coaraze . Provence – Fabienne Barre

ANGEL PONCE DE LÉON – BLUE TIME (1961)

coaraze-sundial-6a.jpg (1280×960) — Cadrans Solaires . Ceramic Sundials . Coaraze . Provence – Angel Ponce de Léon

HENRI GOETZ – LE PYTHON ET SA COURONNE EN VERT ET OR (1961)

coaraze-sundial-7a.jpg (1280×1006) — Cadrans Solaires . Ceramic Sundials . Coaraze . Provence – Henri Goetz

SACHA SOSNO (2007)

coaraze-sundial-8a.jpg (1280×960) — Cadrans Solaires . Ceramic Sundials . Coaraze . Provence – Sacha Sosno

“BEN” – BENJAMIN VAUTIER (2008)

coaraze-sundial-9a.jpg (1280×960) — Cadrans Solaires . Ceramic Sundials . Coaraze . Provence – Benjamin Vautier

coaraze-a.jpg (1280×978) — Cadrans Solaires . Ceramic Sundials . Coaraze . Provence

coaraze-sundial-10.jpg (1280×960) — Cadrans Solaires . Ceramic Sundials . Coaraze . Provence

Coaraze Sundial 11 — Cadrans Solaires . Ceramic Sundials . Coaraze . Provence – Benjamin Vautier

ST GEORGES de BOSCHERVILLE . NORMANDY – a complex modern sundial

Published on November 20, 2021 by Rolling HarbourLeave a comment

LES CADRANS SOLAIRES DE ST GEORGES de BOSCHERVILLE

This decorative sundial – one of two – is something rather special. It is both elegant and complex, and must have taken a long time to devise and lay out accurately. It stands in the extensive grounds of the fine Abbey Church of St Georges de Boscherville in Normandy. I managed to get the last small pamphlet in the Abbey bookshop. Even then I failed to understand the sundial properly, and not simply because of my rusty but workable French. I’m not even going to attempt to describe the dial, but it was easy to photograph in detail in its picturesque setting, and I have included a shot of the explanatory plaque at the end for the science-minded.

One fact I learnt is that until WWII, France was on Greenwich Meantime. During the occupation, the Germans changed the time zone to Central European time, a practice that has remained ever since.