| The mining in the Franconian Forest has produced a lot of pits in the area and counts to the oldest mining areas in Germany. Indeed, one searches in the World Wide web in vain according to the information of which are documented by photos or maps. This comprehensive contribution gives you a wide vie ... moreThe mining in the Franconian Forest has produced a lot of pits in the area and counts to the oldest mining areas in Germany. Indeed, one searches in the World Wide web in vain according to the information of which are documented by photos or maps. This comprehensive contribution gives you a wide view into this extended mininig area. Researched and written from Michael Kommer (in german language) |
| People have always been fascinated by precious stones because of their lustre. But not only polished gems shine. Each raw mineral has, such as mica flakes in the river sand show, its very special characteristic luster. Gloss isn't simply measurable. It is usually described by comparison with objects ... morePeople have always been fascinated by precious stones because of their lustre. But not only polished gems shine. Each raw mineral has, such as mica flakes in the river sand show, its very special characteristic luster. Gloss isn't simply measurable. It is usually described by comparison with objects of everyday life ... (in german) |
| The metal extraction by ore leaching (mostly copper) was about 1,000 years BC. known in the Mediterranean, but there are also barely no written records. The in the Middle Ages and in the following Renaissance well-known different procedures were first described in detail by Georg Agricola 1556 in hi ... moreThe metal extraction by ore leaching (mostly copper) was about 1,000 years BC. known in the Mediterranean, but there are also barely no written records. The in the Middle Ages and in the following Renaissance well-known different procedures were first described in detail by Georg Agricola 1556 in his book "De Re Metallica Libri XII". A contribution by Peter Seroka |
| ... Da offene Flammen häufig zu Explosionen von Methangas in Kohlebergwerken führten, schrieben Grubenbesitzer einen hoch dotierten Preis zur Erfindung einer explosionssicheren Lampe aus. So wurde die Davy-Lampe entwickelt. Das Geheimnis war ein simples, engmaschiges, Drahtgitter um die offene Flamm ... more... Da offene Flammen häufig zu Explosionen von Methangas in Kohlebergwerken führten, schrieben Grubenbesitzer einen hoch dotierten Preis zur Erfindung einer explosionssicheren Lampe aus. So wurde die Davy-Lampe entwickelt. Das Geheimnis war ein simples, engmaschiges, Drahtgitter um die offene Flamme. Dieses Gitter verhindert, durch Wärmeableitung, die Entzündung von Gas außerhalb der Lampe. Die Weiterentwicklung war der Einsatz von wiederaufladbaren Akkus statt ... Ein Beitrag von Peter Seroka und Wilhelm W. |