Graduation tower
A graduation tower (occasionally referred to as a thorn house[1]) is a structure used in the production of salt which removes water from a saline solution by evaporation, increasing its concentration of mineral salts. The tower consists of a wooden wall-like frame stuffed with bundles of brushwood (typically blackthorn) which have to be changed about every 5 to 10 years as they become encrusted with mineral deposits over time.[2] The salt water runs down the tower and partly evaporates; at the same time some minerals from the solution are left behind on the brushwood twigs.
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Graduation towers can be found in a number of spa towns, primarily in Germany but also Poland and Austria. The mineral-rich water droplets in the air are regarded as having beneficial health effects similar to that of breathing in sea air.
A large complex of graduation towers is located in Ciechocinek and Inowrocław, Poland.[2] This entirely wooden construction in Ciechocinek was erected in the 19th century by Stanisław Staszic. The complex consists of three graduation towers with a total length of over 2 km. Many tourists visit it for health reasons.
Gallery
- Graduation tower in Bad Dürrenberg
- 18th-century schematic
- Aerosol at Ciechocinek facility
- Graduation towers in Bad Kreuznach
Partial list of towns and cities with graduation towers
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With years of initial construction where available. Does not include modern indoor facilities found in some spas.
- France
- Saulnot (16th century)
- Arc-et-Senans (1775)
- Germany
- Bad Dürkheim (1736)
- Bad Dürrenberg
- Bad Essen
- Bad Karlshafen (1986)
- Bad Kissingen (16th century)
- Bad Kreuznach (1732)
- Bad Kösen
- Bad Münster am Stein (1729)
- Bad Nauheim
- Bad Oeynhausen
- Bad Orb (1806)
- Bad Rappenau (2008)
- Bad Reichenhall (1911)
- Bad Rothenfelde (1777)
- Bad Salzelmen (part of Schönebeck, 1756)
- Bad Salzhausen (around 1600)
- Bad Salzuflen (18th century)
- Bad Salzungen
- Bad Sassendorf
- Bad Soden (part of Bad Soden-Salmünster, 2006)
- Bad Sooden-Allendorf
- Bad Staffelstein
- Eibach (part of Dillenburg, 2004)
- Hamm (2008)
- Lüneburg (1907)
- Rheine (Saline Gottesgabe)
- Salzgitter-Bad (2009)
- Salzkotten
- Poland
- Ciechocinek (three towers: 1824 to 1859)
- Chorzów
- Grudziądz
- Inowrocław
- Konstancin-Jeziorna
- Radlin
- Rabka-Zdrój
- Katowice (from 2018)
- Romania
- Baile Figa (2020)
References
- "Graduation House". www.thermarium.com. Archived from the original on August 10, 2014. Retrieved August 9, 2014.
- Affelt, Waldemar: Wooden masterwork of saline in Ciechocinek, Poland Archived 2011-09-07 at the Wayback Machine, in: Santiago Huerta (ed.): Proceedings of the First International Congress on Construction History: Madrid, 20th–24th January 2003, Instituto Juan de Herrera, Madrid 2003, ISBN 84-9728-070-9