By the use of fire-setting in recent times at Königsberg (Arthur L. Collins, "Fire-setting," Federated Inst. of Mining Engineers, Vol. V, p. 82) an advance of from 5 to 20 feet per month in headings was accomplished, and on the score of economy survived the use of gunpowder, but has now been abandoned in favour of dynamite. We may mention that the use of gunpowder for blasting was first introduced at Schemnitz by Caspar Weindle, in 1627, but apparently was not introduced into English mines for nearly 75 years afterward, as the late 17th century English writers continue to describe fire-setting.
[15] The strata here enumerated are given in the Glossary of _De Re Metallica_ as follows:--
_Corium terrae_ _Die erd oder leim._ _Saxum rubrum_ _Rot gebirge._ _Alterum item rubrum_ _Roterkle._ _Argilla cinerea_ _Thone._ _Tertium saxum_ _Gerhulle._ _Cineris vena_ _Asche._ _Quartum saxum_ _Gniest._ _Quintum saxum_ _Schwehlen._ _Sextum saxum_ _Oberrauchstein._ _Septimum saxum_ _Zechstein._ _Octavum saxum_ _Underrauchstein._ _Nonum saxum_ _Blitterstein._ _Decimum saxum_ _Oberschuelen._ _Undecimum saxum_ _Mittelstein._ _Duodecimum saxum_ _Underschuelen._ _Decimumtertium saxum_ _Dach._ _Decimumquartum saxum_ _Norweg._ _Decimumquintum saxum_ _Lotwerg._ _Decimumsextum 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_, _rauchstein_, _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.