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an old sailor who, for some time, converted one of the old coke 
ovens into a dwelling. The boys of a later date occupied them 
on holidays as play-houses in stormy weather. 
I am told that seventy years ago, coke was made at the ovens 
for the purpose of drying damaged corn, previous to its being 
ground at the adjacent mill. 
Since 1783 immense progress has been made in all that 
appertains to the smelting and manufacture of iron. Now furnaces 
are built circular of comparatively thin brick work, and surrounded 
entirely by strong iron plates; the inner lining being of refractory 
fire brick, separated from the outer portion of the wall by a narrow 
space filled with sand. Recent ones have been built as high as 
from eighty to one hundred feet. 
A bell or cone is used for closing the mouth of the furnace, so 
as to save the “waste gases;” these are conveyed by pipes from 
openings just under the cone, and are used to raise steam and heat 
the blast, which afterwards passes to the blast pipe surrounding 
the hearth with its tuyere branches. 
In the period embracing 1750, blast furnaces produced on an 
average three hundred tons of pig iron annually, while the largest 
constructed of late years yields 24,000 tons in the same time ; in 
fact, the produce of a single modern furnace is equal to nearly one 
and a half times the crude iron made in this country one hundred 
and twenty years ago. 
The cubic contents of the furnace of 1854 were 5,079 cubic 
feet; that of 1863, 16,000 cubic feet; and 1870, 30,000 cubic 
feet. The cost of two furnaces of the last description was 
456,331: 
In the year 1827, a height of furnace of fifty feet, and a 
capacity of from 4,000 to 6,000 cubic feet, fulfilled all the require- 
ments deemed necessary by the iron smelters. 
About the year in question, a manager of Gas Works, Mr. J. 
B. Neilson, of Glasgow, conceived the idea that, by heating the 
air before it entered the blast furnace, an increased intensity of 
temperature would ensue. The conception formed the subject 
of a patent, since so extensively known as the “Hot Blast,” 
