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.

[Pg 127][15] The strata here enumerated are given in the Glossary of De Re Metallica as follows:—

Corium terraeDie erd oder leim.
Saxum rubrumRot gebirge.
Alterum item rubrumRoterkle.
Argilla cinereaThone.
Tertium saxumGerhulle.
Cineris venaAsche.
Quartum saxumGniest.
Quintum saxumSchwehlen.
Sextum saxumOberrauchstein.
Septimum saxumZechstein.
Octavum saxumUnderrauchstein.
Nonum saxumBlitterstein.
Decimum saxumOberschuelen.
Undecimum saxumMittelstein.
Duodecimum saxumUnderschuelen.
Decimumtertium saxumDach.
Decimumquartum saxumNorweg.
Decimumquintum saxumLotwerg.
Decimumsextum saxumKamme.
Lapis aerosus fissilisSchifer.

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.

[Pg 129][16] The history of surveying and surveying instruments, and in a subsidiary way their application to mine work, is a subject upon which there exists a most extensive literature. However, that portion of such history which relates to the period prior to Agricola represents a much less proportion of the whole than do the citations to this chapter in De Re Metallica, which is the first comprehensive discussion of the mining application. The history of such instruments is too extensive to be entered upon in a footnote, but there are some fundamental considerations which, if they had been present in the minds of historical students of this subject, would have considerably abridged the literature on it. First, there can be no doubt that measuring cords or rods and boundary stones existed almost from the first division of land. There is, therefore, no need to try to discover their origins. Second, the history of surveying and surveying instruments really begins with the invention of instruments for taking levels, or for the determination of angles with a view to geometrical calculation. The meagre facts bearing upon this subject do not warrant the endless expansion they have received by argument as to what was probable, in order to accomplish assumed methods of construction among the Ancients. For instance, the argument that in carrying the Grand Canal over watersheds with necessary reservoir supply, the Chinese must have had accurate levelling and surveying instruments before the Christian Era, and must have conceived in advance a completed work, does not hold water when any investigation will demonstrate that the canal grew by slow accretion from the lateral river systems, until it joined almost by accident. Much the same may be said about the preconception of engineering results in several other ancient works. There can be no certainty as to who first invented instruments of the order mentioned above; for instance, the invention of the dioptra has been ascribed to Hero, vide his work on the Dioptra. He has been assumed to have lived in the 1st or 2nd Century B.C. Recent investigations, however, have shown that he lived about 100 A.D. (Sir Thomas Heath, Encyc. Brit. 11th Ed., XIII, 378). As this instrument is mentioned by Vitruvius (50 - 0 B.C.) the myth that Hero was the inventor must also disappear. Incidentally Vitruvius (VIII, 5) describes a levelling instrument called a chorobates, which was a frame levelled either by a groove of water or by plumb strings. Be the inventor of the dioptra who he may, Hero's work on that subject contains the first suggestion of mine surveys in the problems (XIII, XIV, XV, XVI), where geometrical methods are elucidated for determining the depths required for the connection of shafts and tunnels. On the compass we give further notes on p. [56]. It was probably an evolution of the 13th Century. As to the application of angle- and level-determining instruments to underground surveys, so far as we know there is no reference prior to Agricola, except that of Hero. Mr. Bennett Brough (Cantor Lecture, London, 1892) points out that the Nützliche Bergbüchlin (see [Appendix]) describes a mine compass, but there is not the slightest reference to its use for anything but surface direction of veins.

Although map-making of a primitive sort requires no instruments, except legs, the oldest map in the world possesses unusual interest because it happens to be a map of a mining region. This well-known Turin papyrus dates from Seti I. (about 1300 B.C.), and it represents certain gold mines between the Nile and the Red Sea. The best discussion is by Chabas (Inscriptions des Mines d'Or, Chalons-sur-Saone, Paris, 1862, p. 30-36). Fragments of another papyrus, in the Turin Museum, are considered by Lieblein (Deux Papyras Hiératiques, Christiania, 1868) also to represent a mine of the time of Rameses I. If so, this one dates from about 1400 B.C. As to an actual map of underground workings (disregarding illustrations) we know of none until after Agricola's time. At his time maps were not made, as will be gathered from the text.

[Pg 132][17] For greater clarity we have in a few places interpolated the terms "major" and "minor" triangles.

[Pg 137][18] The names of the instruments here described in the original text, their German equivalents in the Glossary, and the terms adopted in translation are given below:—

Latin Text.Glossary.Terms Adopted.
Funiculus Cord
PerticaStabRod
HemicycliumDonlege bretleinHemicycle
TripusStulTripod
Instrumentum cui indexCompassCompass
OrbisScheubeOrbis
Libra stativaAuffsafzStanding plummet level
Libra pensilisWageSuspended plummet level
Instrumentum cui index AlpinumDer schiner compassSwiss compass

[Pg 139][19] It is interesting to note that the ratio of any length so obtained, to the whole length of the staff, is practically equal to the cosine of the angle represented by the corresponding gradation on the hemicycle; the gradations on the rod forming a fairly accurate table of cosines.