gedenktafel
My last idea about refreshing Strassenbrunnen is a memorial plate with the text written with hydrochromic ink
hydrochromic material- materials that produce imagery that disappears or change in colour when exposed to liquid or aqueous solutions.
more at:
http://www.labelsandlabeling.com/scripts/publish/headlines.asp?code=SLF&key=1702&language=en&PageNo=4&pressYr=2006
The plate will memorise the events from the II World War, in which the Strassenbrunnen took a crucial part as a water supply.The "tafel will be placed under the tap of a pump and every time anyone pumps the water out of it it will reveal the hidden text...