Giovanni Francesco Zarbula was a mural painter and sundial designer from Piedmont Italy who created a hundred or more vertical and vertical declining sundials in the French and Italian Alpes between 1830 and 1881. He worked exclusively in Savoy, in Piémont, the Valley of the Ubaye, le Queyras and around Briançon.

Laying out the dial

Zarbula's method was one of observation rather than geometric construction. He did not need to know the latitude or declination of the wall, he did not use tables or calculations; he simply worked directly on the wall. All his dial were within 2° of the 45th parallel, simplifying the construction, and all gave five-minute accuracy.

With a plumb bob he drew a vertical line on the wall, the "Noon Line". He hammered a rod into the wall at right angles to the vertical, the "centre of the dial" C He observed and marked the shadow cast by the tip of that rod throughout a day, the hyperbolic declination line. Using a set of compasses, he determined the line of symmetry on the wall., the "substyle line".

All the rest of the dial was laid out using a 45° square, with a 15° measure at the end. He drew a horizontal line at a point of choice on the dial plate, the "horizon". The square was placed on the substyle facing outwards, sliding into any convenient position where it cuts the horizon. He drew a perpendicular line drawn to that point, the "equatorial". A line was drawn from that point to the centre of the dial, the 18h line (or 6h depending on the declination (d) of the wall). The points where the equatorial crosses the noon line and the substyle line were important. He placed the apex of the square on the substyle line, so the sides passed through the equatorial points (12h and 18h markers). The apex point is called the "auxiliary equatorial centre". A protractor or squares drew off 15° intervals on the equatorial. These were connected to the centre of the dial: the hour lines. The distance from the auxiliary equatorial centre to the equatorial formed the substyle height at that point.

The colours Zarbula treated his paintings as frescos so the body colour was embedded in the supporting lime mortar. He didn't use organic pigments, just oxides. These do not fade in the strong alpine sunlight.

Existing Dials (cadrans)

Of the hundred dials by Zarbula, about 50 have survived, and a further dozen show visible traces. In Hautes-Alpes, seven dials are protected as monument historique.

His dials can be divided into three specific styles Öiseau (Birds), Geometric, Baroque. The birds that appear in the dials of the early 1840s include toucans, jabirus, parakeets and other exotic birds not seen in these mountains. The geometric works of the late 1840s and 1850s are noted or their simplicity, and contain a little trompe-l'œil to give the design some artificial depth. The baroque dials are contain birds, vases, full trompe-l'œil and false-marbling. They contain the symbols of the Second Empire (1852-1870) and Napoleon III particularly the Imperial Eagle. The dials produced after 1865 include the Masonic device of the Square and Compasses: this is co-incidental to the rise and acceptance of masonry on both sides of the Italian French border.

Commune/Village Lieu-dit/Hameau/Hamlet Édifice Region Country Date Protection Notes Coords. Illus. Briançon Saint-Blaise Briançonnais France 1870 Deux cadrans Briançon Place d'Armes Centre d'art contemporain Briançonnais France 1876 Peut-être inspiré de Zarbula Briançon Saint-Blaise Briançonnais France 1870 Briançon Pont-de-Cervières, 4 chemin du Canal-du-Four Briançonnais France 1845 Cervières Maison Delouis Briançonnais France 1839 Deux cadrans Cervières Hôtel de ville Briançonnais France Eygliers Le Cros Briançonnais France 1841 La Salle-les-Alpes Les Pananches Chapelle Saint-Jean-Baptiste Briançonnais France 1879 Attribué à Zarbula La Salle-les-Alpes 38 rue de la Guisane Briançonnais France 1841 Puy-Saint-André Pierre-Feu Briançonnais France 1871 Puy-Saint-André Briançonnais France Puy-Saint-Pierre Le Pinet, 2 rue de Jérusalem Briançonnais France 1842 Deux cadrans Saint-Chaffrey Le Villard-Laté, 27 rue des Trois-Fontaines Briançonnais France 1847 Saint-Martin-de-Queyrières Bouchier Briançonnais France 1853 Saint-Martin-de-Queyrières Prelles Briançonnais France 1845 Saint-Martin-de-Queyrières Prelles Briançonnais France Saint-Martin-de-Queyrières Église Saint-Martin Briançonnais France Les Orres Le Mélezet Les Orres France 1853 Arvieux Le Coin Maison Jean-Paul Blanc Queyras France 1830 Superposition de cadrans, l'un d'eux pouvant être de Zarbula Arvieux Queyras France 1857 Arvieux Les Escoyères Queyras France 1842 Arvieux Les Escoyères Chapelle Saint-Roch Queyras France 1857 Château-Ville-Vieille Ville-Vieille Queyras France Attribué à Zarbula Château-Ville-Vieille Clot-du-Riou Queyras France Deux cadrans Château-Ville-Vieille Ville-Vieille Queyras France 1843 Château-Ville-Vieille Ville-Vieille Queyras France 1843 Château-Ville-Vieille La Rua Queyras France Molines-en-Queyras La Rua Église Saint-Romain Queyras France 1849 Saint-Véran Les Forannes, la Pointe du Jour Queyras France 1840 Saint-Véran La Raux Queyras France 1840 Saint-Véran Ferme de Mathieu Romain Queyras France 1840 Saint-Véran Haut-Forranes Queyras France 1840 Saint-Véran Pierre-Belle Queyras France 1840 Saint-Véran Les Gabelous Ancienne douane Queyras France 1858 Saint-Paul-sur-Ubaye Petite-Serennes Ubaye France 1860 Saint-Paul-sur-Ubaye Maljasset Ubaye France 1860 Pragela Souchères Basses Chapelle Val Cluson Italie 1872 Pragela Traverse, 6 via Nazionale Val Cluson Italie Pragela Villarmont Val Cluson Italie 1872 Sauze di Cesana Rollieres Chapelle Val Cluson Italie 1870 Deux cadrans Sestrières Champlas du Col, 28 via Nazionale Val Cluson Italie 1870 Sestrières Champlas du Col, 7 via Nazionale Val Cluson Italie 1870 Sestrières Borgata Val Cluson Italie 1872 Sestrières Borgata, 14 via del Colle Val Cluson Italie 1872 Sestrières Borgata, 12a via del Colle Val Cluson Italie 1872 Usseaux Balboutet Val Cluson Italie 1833 Deux cadrans Névache Ville-Haute Vallée de la Clarée France Val-des-Prés Pra-Premier Vallée de la Clarée France 1843 Val-des-Prés La Vachette Vallée de la Clarée France 1840 Val-des-Prés La Vachette Vallée de la Clarée France 1852 Valloire Valloire France Valloire Les Verneys Valloire France Vallouise Maison de Bardonèche Vallouise France 1840 Deux cadrans Vallouise Le Villard Chapelle Saint-Sébastien Vallouise France 1869 Deux cadrans Valserres Les Trancs France 1854

References Footnotes

References

External links Zarbula's Sundials