IRON  AND  STEEL IN BRITAIN
Early attention to stack size outside this country is illustrated by
the following data:
TABLE  40
stack size 1870-1930 (tons)
Germany	U.S>A.
Year         U.K. Average         Ilsede Hutte	Edgar Thomson
Works	Works
1870	30	55	—
i875	34	—	70
1880	46-4	no	134
1885	57*6	144	20°
1890	64-6	192	428
1895	75-8	226	—
1900	78	244	700
In 1904 Jeans gave the following comparison, in commenting on
the effect of furnace size:
Great Britain	U.S.A.
Average output*           25,000 tons	60,000 tons
Blast pressure                  4 to 6 Ib.	10 to 20 Ib.
Volume of blast                 small	laige
Ore per ton                      2 \ tons	if tons
Iron (per cent)                     38	50
Life of furnace                    long	short
Labour cost per ton     33. 6d. to 4$.	2s. to 2s. 6d.
In 1911 in Germany the minimum output per furnace was 45,700
tons in Lorraine and Luxembourg: the average in the Saar was
50,000 tons, and in the Rhineland 67,000 tons. The smaller output
per furnace in Britain (30,000 tons) was attributed to small units,
inadequate appliances (too old and too weak for the function they
had to perform) and the high expenditure on labour.
In 1915 the different iron-making districts in Britain were rated
in the following order for average furnace output:
Tons per armum	Tons per annum
South Wales	65,000	Durham	39>4oo
Cleveland	45,800	Lines	33>3oo
Cumberland	40,900	Scotland	15,500
About the same time the minimum annual production per furnace
in the U.S.A. was 80,000 tons in Alabama and the maximum
135,000 tons iu Illinois.
* Average output is greater than average capacity in times of depression as the larger
and more efficient fijrnaces are kept running. Conversely, in times of prosperity and
large total production the smallest faniacea arc included an the average output figures.