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the manufacture of wrought iron. 287
Table 56. Number of Forging Hearths and Puddle Furnaces employed.
Annually Scrap smelting hearths Wallem hearths [-Franche-Comté-] {+Franche- Comté+} hearths German hearths Puddling furnaces [-Lancashire-] {+Lanca- shire+} hearths Total
1891-95 .... 10 25 43 4 328 410
1896-00 .... 15 23 18 1 4 287 348
1901-05 .... 13 25 13 — 3 275 32!»
1906-10 .... 8 22 5 — 1 239 275
1911...... 7 22 4 - _ 199 232
1912...... 8 21 3 _ 201 233
1913...... 10 21 2 — — 202 235
labour on tbe part of the workmen: an increased output was thus thereby
obtained, while a saving of iron, charcoal and labour was effected.
Export of Wrought Iron. See the Table 57. It may be said,
that by far the greater part of the wrought iron produced is exported
in the form of "bar iron" (stångjärn) or "rough bars" (råskenor), but
also to some extent in the shape of blooms (smältstycken).
Import of Wrought Iron. There is no import of wrought iron into
Sweden.
The chief Processes used in the Manufacturing of Wrought Iron.
A brief account of these processes is furnished below.
The most ancient known method of preparing malleable iron (wrought iron)
in hearths from pig iron was that known as tysksmide, or "German forging"
which was introduced into Sweden at the beginning of the seventeenth century.
This kind of forging was performed in an open hearth composed of coarse
cast-iron slabs, in which the pig iron was melted down with charcoal. After
the smelting it was broken up from the bottom of the hearth with heavy iron
bars in order to be remelted, and this operation was sometimes repeatedly
performed. The silicon and carbon in the pig-iron was oxidized in the smelting,
and a lump (smälta) of soft slaggy iron was obtained. The latter was belaboured
with a heavy hammer, and afterwards cut up into smaller pieces, called
smältstycken or "blooms".
In a "German hearth" (tyskhärd) 2 to 3 tons of bar iron were produced per
week with a consumption of more than 200 hectoliters of charcoal per ton. The
waste was 18 %.
The method was gradually improved.
An improved process was introduced in 1740 from France under the name of
Wallonsmide or Walloon forging into the Dannemora mining district, where it is still
Table 57. Export of Wrought Iron.
Annually Blooms and rough bars tons Bar iron tons
1891-95 . . . 11616 168 563
1896—00 . . . 21 453 166 626
1901-05 . . . 21 740 172 680
1906—10 . . . 26 380 143 780
1911 ..... 27 600 129 200
1912 ..... 35 500 131200
1913 ..... 39 500 129 400
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