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vi. mining and metallurgical industry.
the invention of the Thaléns Magnometer (about 1870) for measuring
magnetic horizontal intensity as well as the Tiberg Inclination Balance
(about 1880) and the Thomson-Thalén vertical power balance (1899) for
measuring magnetic vertical intensity. The magnetic horizontal and
vertical intensity maps of mining areas at the surface and the magnetic
force-lineas plans (Ikraf tpilkar tor) of mining areas underground which have
been drawn up with the aid of measurements made with these
instruments have greatly facilitated the work in Swedish iron mines. These
Swedish methods have indeed been coming more and more into use abroad
and particularly in America.
In addition to the magnetic investigation methods, prospecting by means
of diamond-boring has been extensively resorted to in Swedish ore mines.
On account of the ease with which it is manipulated and the moderate cost
at which boring can be carried out with it, the Croelius’ diamond drill, with
a bore-hole diameter of 35 millimeters has been almost the sole make
employed.
Mine Maps and Mine Surveying. In the Mining Act of the 16th
May 1884 it is prescribed that all mines shall be mapped out by specially
authorized mine surveyors, and that the maps shall be completed to date
year by year. The maps are drawn up in duplicate, one of which is kept
as a public document in the Office of Mine Maps belonging to the Board
of Trade (Kommerskollegium). Maps of ore mines shall be drawn up on
a scale of 1:800 and be executed in accordance with a normal chart
(normalkarta) determined by the Board of Mines.
In accordance with this normal map only one horizontal section is drawn on
each sheet, and the map sheets shall contain not only the configuration and
the position relatively to one another of the working rooms, but also in certain
fixed colours the geological conditions of the mine. Besides the plane charts
each mine map shall have attached to it at least one longitudinal projection
and cross sections through the mine.
In the case of coal mines the scale 1 : 1 500 is prescribed, and the maps
are to be drawn in accordance with a normal map prepared expressly for coal
mines.
As early as 1628 a Royal Ordinance was promulgated in Sweden providing
that all mines in Sweden should be surveyed and mapped, and in 1629 the
first Swedish mine map (of the Falun Mine) was drawn up.
Mining Legislation.
Ore Mines. In persuance of the Mining Act of the 16th May 1884 as amended
and supplemented by the subsequent Acts of the 20 Oct. 1899, the 5 June
1901, and the 12 August 1910, any Swedish subject has the right to acquire an
inmutning or preliminary claim to mineral deposits which contain (a) the ores
of the following minerals: gold, silver, platinum, mercury, lead, copper, iron,
(with the exception of lake and bog ores), manganese, chrome, cobalt, nickel,
zinc, pewter, titanium, molybdenum, tungsten, vismuth, arsenic, and antimony;
(b) iron pyrites, magnetic pyrites, and graphite; and (c) on Crown lands which
have not been disposed of apatite and magnesite — provided that these mineral
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