the invention of the Thalen’s Magnometer (about 1870) for measuring
magnetic horizontal intensity as well as the Tiberg Inclination Balance
(about 1880) and the Thomson-Thalen 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 (kraftpilkartor) 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 Su rv ey in g . 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 (nor-
malkarta) 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.
I 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 §||p! provided that these mineral
deposits are situated at least 200 meters from dwellings, building sites, and
galThe claimer (inmutare) has the right to carry,on preliminary work ( forsoks-
arbeten) within the urea claimed, which 'comprises a circumference with a radius
of 100 meters. The proprietor of the ground is entitled to participate with
the claimer as to half in the work and in the profit that may accrue. When
a deposit to which a preliminary claim has been acquired has been exposed and
a sample of the ore obtained, an area called utmdl not exceeding 200 meters in
length and breadth shall be assigned to the claimer. Within this area the
owner of the mine has the sole right of carrying on mining work both at the
surface and underground. The downward limits of the utmdl shall be reckoned
perpendicularly. _ . .
Within each inmutning or utmdl a certain amount of mining work or mine
construction work shall be carried out yearly. I f the claimer neglect to execute
this work, the mining works will be declared forfeited (sonad) and the rights
founded on the claim certificate (mutsedel) forfeited.
In the lan of Norrbotten certain areas at and in the vicinity of the big iron,
ore fields are separated of as “State Mining Fields”, and within these areas
claims cannot be acquired.
Coal Mines. Stone coal deposits are not eligible for inmutning. The right
to investigate and work such deposits under the Act of the 28th May 1886 is
dependent on a special concession (Concession) granted by Government. The
concession may not comprise a larger area than one thousand six hundred hectares.'
The holder of the concession is under obligation to pay a certain fee
yearly to the proprietor of the ground, and it is moreover incumbent on him
to perform . annually a certain amount of mining work, as prescribed in the
concession.
2. IRON AND STEEL INDUSTRY.
Since time immemorial the manufacture of iron has been one of the most
important branches of industry in Sweden and Swedish iron is famed for
its superior qualities.
This superiority is to be ascribed mainly to two causes: an abundance
of good pure ores, and the use of charcoal in the production of pig iron.
As long as charcoal was used exclusively also in other parts of the world
in the production of pig iron, Sweden’s share in that production was very
considerable, even quantitively.
However, as long ago as 1730 coke began to be used in English blast
furnaces, and in 1785 a new fining process called “ puddling” was invented
in England, and in that process coal could be used.
Owing to these changed circumstances, Sweden, who possesses but little
fossil coal, was compelled to assume, considering the quantity, a more and
more modest position among iron-producing countries, whereas in respect
to quality she still leads. And it may be presumed that she will contrive
to maintain this lead far into the dim future.
In the middle of the eighteenth century Sweden seems to have made