Page:Popular Science Monthly Volume 33.djvu/235

Rh rocks. Next comes the Odenwald. The northern part of this lias not been recently described (18) as a whole, although there is much of petrographic interest. The Rothliegendes, with its amygdaloids, is broken through by basalt, which at the Rossberg has glass inclosures, at the Oetzberg sandstone inclosures. In Darmstadt is a museum, which may be of assistance. South of Darmstadt, around Castle Frankenstein, is a mass of gabbro and diorite with many interesting varieties. Near Auerbach marble occurs, and in sundry other places garnet rocks.

We now are approaching Heidelberg, a town well placed as a center for geologic excursions. Benecke and Cohen (19) have, however, one fault as guides. They are too complete; so that a few remarks may not be out of place. North of Heidelberg the petrographer will find much and the paleontologist nothing, for the well-known Triassic sandstone and the Rothliegendes are not fossiliferous. South of Heidelberg, however, past the cadmium and zinc mines of Wiesloch, we can get a continuous section through the whole Trias well up into the Jura. Lime-pits and cement-works quarries afford exposures into the weaker beds, and the workmen have learned to save the ammonites, etc. East of Heidelberg, following up the beautiful valley of the Neckar, we come to the nephelinite of the Katzenbuckel, a stone in places so coarse as to yield when weathered distinct crystals of nepheline.

In the Friedrichsbau of the old university is an interesting collection of maps, models, and specimens. There is also a school of petrography much frequented by students of all nations, especially Americans. On the steep way up to the castle from the Prinz Carl Hotel is the natural curiosity store of Blatz, the oldest house in Germany, I believe, with very reasonable prices. The granite on which the castle stands is best exposed on the Valerien-Weg, a pretty path just beyond the Carlsthor. Leaving the valley of the Neckar, the hills gradually grow lower and more rounded till near Baden we approach the Black Forest through which the Black Forest Railway winds its bold and tortuous way. Geologically this is essentially like the Odenwald, and Eck's inexpensive maps (20) will serve as guides. I should not pass Strasburg and Freiburg without mention. The one, with a university, fine collections, and a geological survey, is the natural center for excursions in Alsace—not so pleasant just now, for geology has less regard for frontiers than have the French and Germans. The other has also university collections, and may be made the center for excursions in the Black Forest or to the Kaiserstuhl, an isolated volcanic peak rising out of the Rhine, and a locality for limburgite, perowskite, and zeolitic minerals. It is mostly cultivated in those oblong patches characteristic of peasant proprietorship.