Discovering the Oltre il Colle Mineralogic Museum

In alternative, miners used to fill the cracks with quicklime that, once wet, enlarged them. Another method was the insertion into the cracks of dry wood wedges that, once wet, grew up enlarging the crack. An old technique was firing a wood pile close to the rock. The hot rock was quickly cooled with water. This way miners created many little cracks in the rock. This method had a problem: the smoke entered the galleries. At the end of the XVI century the adoption of gunpoweder made exploitation faster, even if still dangerous. One of the most dangerous operations was laying the mines.