Mit ii'iioi.ocit Ai, ^■^•|^^ or ii in(;aií 'i . 127 



Volcanic actjvity and íoldiiig, bulh oii a gn'at scalc, scciii to havc attended 

 the defoinmtive inovcincnts, which havc crcatod also thc lowor moimtains 

 Holitarily stiinding in the cential parts of the country. We .nay immediateiy 

 point out, tliat the volcanoes of long pást ages are of inestimable value 

 to this country. Aut of theii' depth eiose the innumerabl(> nietalHc veins 

 oontaining gold , silver, copper, lead a. s. o. ; the ini|K)rtant la wniat(MÍals 

 of H\ingorys niining indust ly. 



The last period of volcanic eruption was Ihat of basahic la vas. This 

 ct)mpact but not veiy brit t le lock procuiis a most excellent matériái for 

 road construction, as does also the trachyte and andesite. l'here are cases 

 when volcanic ashes give a íiistrate trass, equaling portland cement in 

 every respcct. The quantity of these volcanic ashes in the Pannonian 

 basin is so large ihat it would be sufficient, to supply the whole of Europe's 

 demand for l)eton. The effects of the last volcanic activities caused somé 

 changfs in the rocks, making them suitable to supply other industrifs 

 witli* valuable lawmaterials ; sach are alunite, kaohn, loam etc, and aiso 

 the precious opál, the histre of which as regards richness in colours is not 

 to be found in any other part of the world. The volcanic actions havt> not 

 ceased evén up to our very days. They are surely reduced in (^fficacy but 

 the products of this conslant aclivity are nőne the less valuable. Gaseous 

 emanations as the last signs in our days of volcanic activity are the origin 

 of hot springs and mineral Avateis. The hygienic value of Some of these 

 hot springs is world famed. 



III.^Thc liy(lro<|raphical iinily of the Hungárián territory 

 an<l the ílíingor of inundatíons. 



The pi'rf( ct hydrographical unity of the hasin surrounded by the 

 Oarpalhians is inteiiuptí d only by three very small rivers such as the 

 Poprád, Olt and I>tszterc'ze. 



The axis of this hydrographical unity is the river Danube, which 

 coming fiom the Moravian plain enters the Hungárián basin through the 

 western door at Dévény. Brtween entering the country and leaving it 

 again the D.und)e flows along tectonic lines, draining from Dévény till 

 P^ziás all the ri\ers of the Hungárián basin. ■ 



l^)th the chanuel of the river Tisza flowing from Xorth to South and 

 that of the Maros ciossing the (jreat Plain are tectonic lines too. The 

 elevated territories drained by them represent more than Vaof the country's 

 mountain districts. A predominant part of the territoiy drained by the 

 Tisza belongs to th(^ Great Plain, indeed, but owing to the slight gradieni 

 of the surface cíius^^s the waters very slow flow off c<)mpared with 



