2 26 THE POPULAR SCIENCE MONTHLY. 



marsliy, but has been in this century greatly improved by a pro- 

 cess of controlling the mountain-streams and making them de- 

 posit their detritus so as to increase the grade. Notice on the 

 west side how the layer of tufa overlying Pliocene sands resists 

 erosion and makes flat-capped, naturally-walled hills. The site 

 of Orvieto is a good example. In Florence are also collections, 

 but the Tuscan Exposition of 1887 will probably liave altered 

 their arrangement. 



At Prato, a little north of Florence, famous for vanilla-drops 

 and a bronze screen, we may leave the train and walk a few miles 

 to Monte Ferrato, where there are quarries of a beautiful gabbro, 

 pietra verde, much used for decoration. It is surrounded by ser- 

 pentine and porcelanized slate. At the Cave del Acqua it is 

 most coarse and fresh. Soon after we turn sharply and cross 

 the Apennines over to Bologna (3, 23). As from Turin to Genoa, 

 so here — the whole range is Tertiary and the same horizons 

 which in Belgium we saw hardly disturbed since their deposi- 

 tion, are here highly metamorphosed. The University of Bo- 

 logna has a fine, well-ordered collection, especially to be visited 

 by those who will tarry a little in the Euganeans, where Petrarch 

 was born (10). Thus they will get an idea of the peculiar vol- 

 canic products awaiting them. There are still hot baths at Bat- 

 taglia. 



Every one will notice the Holland-like character of the coun- 

 try about Ferrara, and the way the Po flows along with its bed 

 above the adjacent fields, over pebbles from the Alps far away, 

 and will wonder how long it will be before the lagoons about 

 Venice will in their turn become fertile plains. We have been 

 around Italy. We may now go via Verona — don't pay the awful 

 prices the man at the amphitheatre asks for his fossils — and 

 Trent up into the Tyrol. The Tyrol and Switzerland are geo- 

 graphically but not geologically divided, so I need add only a 

 reference to the work of Von Buch on the dolomites (10), and 

 that of the Austrian geologists (12*). In Innsbruck is a very 

 full geognostic collection. 



We may go hence to Munich, where Groth's new laboratory 

 affords every luxury to the mineralogist and petrographer, and 

 Zittel conducts the most famous school of paleontology in the 

 world, and Gumbel directs the Bavarian survey (3). Or the 

 route to Vienna, by way of the Salzkammergut, is interesting, 

 and the city is a focus of scientific interest, with a magnificent 

 university. 



Farther east the casual tourist will scarcely go, although no 

 country of Europe surpasses Hungary in geological interest, 

 where there are several important mining centers. I have been 

 as far as Constantinople, with no extra trouble except that 



