BOOK V. 127 



neath which is the sixth stratum, likewise dark, but rough and three feet 

 thick. Afterward occurs the seventh stratum, hkewise of dark colour, but 

 still darker than the last, and two feet thick. This is followed by an eighth 

 stratum, ashy, rough, and a foot thick. This kind, as also the others, 

 is sometimes distinguished by stringers of the stone which easily melts in 

 fire of the second order. Beneath this is another ashy rock, light in 

 weight, and five feet thick. Next to this comes a lighter ash-coloured 

 one, a foot thick ; beneath this lies the eleventh stratum, which is dark and 

 very much like the seventh, and two feet thick. Below the last is 

 a twelfth stratum of a whitish colour and soft, also two feet thick ; the 

 weight of this rests on a thirteenth stratum, ashy and one foot thick, whose 

 weight is in turn supported by a fourteenth stratum, which is blackish and 

 half a foot thick. There follows this, another stratum of black colour, 

 likewise half a foot thick, which is again followed by a sixteenth stratum 

 still blacker in colour, whose thickness is also the same. Beneath this, and 

 last of all, lies the cupriferous stratum, black coloured and schistose, in which 

 there sometimes glitter scales of gold-coloured pyrites in the very thin sheets, 

 which, as I said elsewhere, often take the forms of various living things.*' 



The miners mine out a vena dUatata laterally and longitudinally by 

 driving a low tunnel in it, and if the nature of the work and place permit, they 

 sink also a shaft in order to discover whether there is a second vein beneath 

 the first one ; for sometimes beneath it there are two, three, or more similar 

 meteil-bearing veins, and these are excavated in the same way laterally and 

 longitudinally. They generally mine vence dilatata lying down ; and to 



"The strata here enumerated are given in the Glossary of De Re MetaUica as follows : — 

 Corium terrae Die erd oder Uim. 



Saxum rubrum . . . . Rot gebirf;e. 



Alter um item rubrum Roterkle. 



Argilla cinerea Thone. 



Tertium saxum . . Gerhulle. 



Cineris vena .. .. .. .. Asche. 



Quarlum saxum . . Gniest. 



Quintum saxum . . . . Schwehlen. 



Sextum saxum . . Oberrauchstein. 



Septimum saxum Zechstein. 



Ociavum saxum Underrauchstein. 



Nonum saxum Blitterstein. 



Decimum saxum Oberschuelen. 



Undecimum saxum . . Mittelstein. 



Duodecimum saxum . . UnderschtuUn. 



Decimumtertium saxum Dach. 



Decimumquartum saxum . . Norweg. 



Decimumquintum saxum Lotwerg. 



Decimumsexium saxum Kamme. 



Lapis aerosus fissilis Schifer 



The description is no doubt that of the Mannsfeld cupriferous slates. It is of some 

 additional interest as the first attempt at stratigraphic distinctions, although this must not 

 be taken too literally, for we have rendered the different numbered " saxum " in this connection 

 as " stratum." The German terms given by Agricola above, can many of them be identified 

 in the miners' terms to-day for the various strata at Mannsfeld. Over the kupferschiefer the 

 names to-day are kammschale, dach, faule, zechstein, rauchwacke, rauchsiein, asche. The 

 relative thickness of these beds is much the same as given by Agricola. The stringers in 

 the 8th stratum of stone, which fuse in the fire of the second order, were possibly calcite. 

 The rauchstein of the modern section is distinguished by stringers of calcite, which give it at 

 times a brecciated appearance. 



