or HARTZ, a forest and mountain in the principality of Grubenhagen in Germany, in length 48 miles, and in breadth about 20. The forest which covers the mountain consists of a great variety of wood, which is of much importance to the numerous forges and manufactories of iron, which have been long established in this district. Beside abundance of the ores of iron, the Hartz yields other metallic ores in considerable quantity, as those of copper, lead, silver, zinc, and sometimes gold. The mining operations have been long carried on to a very great extent in this mountainous region.