I read a while back on the thread about ancients ...
the enscribed stones found in the side of old river beds inscribed with a date and a comment about the climate or somesuch
Here it is:
Drought Stones Pass Messages of Warning to Europeans
The recent unusually warm weather has resulted in a number of important archaeological sites being revealed as vegetation has died in Europe. The recent drought has also brought to the surface some fascinating archaeological discoveries that have long been hidden in rivers. In the Czech Republic, the low level of water in the River Elbe is revealing large engraved stones from the early modern period and earlier. These are hunger or drought stones that were carved in previous droughts and have now been revealed as the water level has fallen. They are allowing us an insight into how drought impact Europeans and how they responded to extreme weather. History of Drought Stones
In the early modern and the medieval period, the population lived at a subsistence level and any problems with the harvest could lead to hunger or even outright famine. The harvest was dependent on the weather and events such as drought could have cataclysmic consequences. When the river level fell the population knew that there were hungry times ahead. Researchers have established - based on the study of tree rings - that Europe has experienced major droughts in the past few centuries.
Hunger stone found on the Elbe at Decin. (Image: idecin) The exposure of the stones
The recent high temperatures in Europe have been record-breaking. The River Elbe that rises in the Czech Republic is one of the great European Rivers. The persistent lack of rainfall means that the level of this river has fallen in a way not witnessed in decades. Over a dozen drought or hunger stones have been exposed by the rapid fall in the water level. These are known in German as 'Hungersteine'.