Throughout the world valuable sculptures are threatened with serious damage from air pollution. The stone?
Throughout the world valuable sculptures are threatened with serious damage from air pollution. The stone cultural memorials have for centuries with-stood the natural processes of ageing and weathering, but now their deterioration has been greatly accelerated by industrial gases in the atmosphere. New methods of protecting the works are urgently being developed.
SYNOPSIS: Corrosive industrial waste gasses are causing damage in a few decades that by natural means would take centuries. But a major campaign launched by UNESCO is trying to stop the decay, beginning with the Acropolis in Athens. The job will take much research and technical effort.
West Germany can already display examples of new methods of building preservation. A major project has been the restoration of the Cologne Cathedral, where the entire facade is being protected by a plastic material. The spray-on process is like providing a rain-coat for the building. But the most valuable pieces need other treatment, so another method is being tested at the Residence of the south German baroque city of Wurzburg. Here, fine sculptures are being copied.
Increasing damage means that the masterworks of baroque sculpture must be taken to closed rooms and, to maintain the original appearance, they will be replaced by replicas.
Tedious work with a mixture of sand and water replaces the missing parts of the original sculpture. This material can be removed later. A coating of artificial rubber is applied, to make a mild for a true copy of the work.
The rubber mild is stabilised by a plaster cast and then carefully filled with a liquid which hardens into artificial stone. This is better than natural stone at withstanding the rigours not only of the weather, but of the acid pollution in the air. The artificial stone is a product of years of experiment. When it is hard the rubber mild is stripped off, and the once damaged sculpture is rendered in a copy as near as possible to the mason's original intentions.
With the original consigned to the protection of a museum, the weather-resistant replica is put in place to return the structure to its true form. This building is now nearer to its original appearance than it has been for nearly two-hundred years.
For this reason it can be of interest to historians, and for visitors, a plastic palace can give as much enjoyment as the authentic one made of deteriorating stone.