Xl NOTES. 



of Marihaye, near Val-St.-Lambert, in the valley of the Meuse, is 

 1157 French feet (1233 Engl.), according to M. Gernaert, Inge'nieur des 

 Mines. The mines of greatest absolute depth are for the most part situated 

 in such elevated mountain valleys or plains, that their deepest portions either 

 do not descend to the level of the sea, or reach but a little way below it. 

 Thus the Eselschacht, at Kuttenberg, in Bohemia, which is now inaccessible, 

 had the prodigious absolute depth of 3545 (3778 Engl.) feet (Fr. A. Schmidt, 

 Berg gesetze der osterr. Mon. Abth. i. Bd. i. S. 32). At St.-Daniel and 

 at Rorerbiihel (Landgericht kitzbuhl) there were, in the 16th century, excava- 

 tions 2916 French feet deep. The plans of the works, dated 1539, are still 

 preserved (Joseph von Sperges, Tyroler Bergwerksgeschichte, S. 121). Com- 

 pare also Humboldt, Gutaehten iiber Herantreibung des Meissner Stollens in 

 de Freiberger Erzrevier, printed in Herder iiber den jetzt begonnenen Erb- 

 stollen, 1838, S. 124. It may be suppose^ that the knowledge of the extra- 

 ordinary depth of the Rorerbiihel had reached England at an early period, for 

 I find it stated in Gilbert de Maguete, that men had penetrated into the crust 

 of the earth to depths from 2400 to 3000 feet. " Exigua videtur terra 

 portio quee unquam hominibus spectanda emerget aut eruitur : cum profundius 

 in ejus viscera, ultra eflorescentis extremitatis corruptclam, aut propter aquas 

 in magnis fodinis, tanquam per venas scaturientes, aut propter ae'ris salubrioris 

 ad vitam operariorum sustinendam necessarii defectum, aut propter ingentes 

 sumptus ad tantos labores exautlandos, multasque difficultates, ad profundiores 

 terrse partes penetrare non possumos ; adeo ut quadrigentas aut (quod ra- 

 rissime) quingentas orgyas in quibusdam metallis descendisse stupendus 

 omnibus videatur conatus." Gulielmi Gilberti Colcestrensis, de Maguete 

 Physiologia nova. Lond. 1600, p. 40. 



The absolute depth of the mines in the Saxon Erzgebirge, near Freiberg, 

 are: in the Thurmhofer Zug, 1824 (1944 Eng.) feet; in the Hohenbirker 

 Zug, 1714 (1827 Eng.) feet: the relative heights are nearly 626 and 620 

 (677 and 277 Eng.) feet, assuming the elevation of Freiberg above the level 

 of the sea, according to Reich's recent determination, to be 1191 (1269 Eng.) 

 feet. The absolute depth of the rich aud celebrated mine of Joacliimsthal in 

 Bohemia (Verkreuzung des Jung Hauer Zechen-und Andreas ganges) is 1989 

 (2120 Eng.) feet ; so that assuming from Herr von Dechen's measurements 

 the ground at the surface to be about 2250 (2388 Eng.) feet above the level 

 of the sea, it follows that the excavations have not yet reached that level'. In 

 the Harz, the Samson mine at Andreasberg has an absolute depth of 2062 

 (2197 Eng.) feet. In what was Spanish America, the deepest mine with 



