Neptune Fountain, Dolní square, Olomouc, Czech Republic
|Address:||Dolní náměstí, 779 00 Olomouc|
|Description of work:||Restoration survey
Restoration of the Neptune Fountain
|Investor:||The City of Olomouc|
|Contractor:||GEMA ART GROUP a.s.|
The historic centre of the town of Olomouc rightly belongs among the urban conservation areas of the Czech Republic. The six fountains from the era of High Baroque form part of the town’s unique historic heritage. The fountains originally had the entirely practical function as reservoirs of water for the burghers of Olomouc, but their intrinsic artistic and historic value, especially of their sculptures with Classical motifs, grew over the centuries.
The choice of the sculptural motifs was influenced by the legend of the town’s beginnings, according to which Olomouc had been founded by Gaius Julius Caesar himself in the year 57 as a military fortification. The name Olomouc is supposed to be a corruption of the original “Julimontum”. Nevertheless, historians place the origin of the legend to the 15th century, the era of humanism.
The six fountains are ornamented with sculptures of the ancient Roman gods Neptune, Saturn, Jupiter, Mercury and Triton, the demigod Hercules and the Roman politician and army commander Caesar. GEMA ART GROUP a.s. was involved in the restoration of the fountain with the statue of the god Neptune. The fountain dates back to 1683; the statue is the work of Gdansk sculptor Michael Mandík and the water basin in the shape of a cross of the stonemason Václav Schüler. The statue of Neptune is actually a group of sculptures: in the centre is the mighty figure of Neptune holding a copper downwards pointing trident. By means of this gesture the Roman god of the sea is supposed to safeguard the town from floods. The figure of Neptune is surrounded by a quartet of water spouting gargoyles in the shape of horses.
Perůtka, M.: Olomouc. Historické město a okolí, České Budějovice 2005
The oldest Baroque fountain in Olomouc has already been the object of restoration several times in the past. The first significant repair was carried out in 1962, when one of the horses’ heads was reconstructed. By 1978 the fountain was in such a poor state that its replacement by a copy was under consideration. This plan was eventually abandoned and the damaged stone was instead secured and conserved. Several partial repairs were undertaken in the following years.
The fountain had been built from siliceous sandstone, deterioration of which had led to problems with water leakage from the basin and a comprehensive restoration of the fountain was paramount.
Before the complete restoration of the fountain could commence a specialist survey was carried out to establish the extent and causes of the deep stone corrosion. For this purpose samples of both stone and of various repair materials were taken. The composition of incrustations on the surface of the fountain and of repair materials as well as levels of water absorption in the stone were ascertained from these tests.
Testing of methods of cleaning and thinning of crusts were also carried out. A probe was laid on the outside of the fountain in order to compare various methods used for filling the cracks during previous repairs. Further probes were inserted in the area of the corroded clamp holding one of the horses to the main sculpture.
Restoration of the Neptune fountain:
The restoration survey had found that the main cause of the stone degradation was the presence of scale deposits, which affected its water absorption and parapermeability and caused it to fall apart. Degradation caused by calcareous sulphate was discovered in the lower parts of the fountain. In the areas of rain shadow crusts formed and mosses grew in the pointing of the stone steps. Corrosion of the individual bronze clamps holding together the stone blocks also caused problems. Various past repairs were made using unsuitable materials, which became loose and led to water leakage.
Dirt deposits were removed using a low pressure steam jet and any residue was removed with scalpels. Scale deposits were eliminated chemically using citric and hydrochloric acid and a carbon dioxide solid jet spray. In some places deposits of asphalt were found; these were first loosened using acetone and then removed mechanically.
Mildly corroded areas were treated with an anticorrosive coating, severely affected ones were completely replaced.
Due to the increased presence of salts it was necessary to apply cellulose and distilled water compresses to the stone. Cracks were infilled with injections of epoxide resin. The leg of one of the horses had to be glued together with polyester resin and secured by insertion of an anticorrosive peg. All surfaces were consolidated using a strengthening agent based on esters of silicic acid.
To conclude retouching was carried out using grouts made of siliceous sand and hydraulic binder and coloured with iron pigments. Localized colour discrepancies were corrected by application of a colour glaze.
Repair of the water supply to the fountain:
Water supply to the fountain is located in a stone tank underneath the sculptural group and all of it was damaged by corrosion. Contemporary exits of the water jets are different from the original ones, no longer functional, which were placed in the heads of the horses and the figure of Neptune.
The pointing of the tank was renewed using single component silicone rubber. The surface of the pointing was sealed using mineral based mortar.