286 PROCEEDINGS OF SECTION B. 
to have the slag forced to deliver at a higher level outside the 
furnace than it lies inside. It is satisfactory only when small 
quantities of matte are being produced. 
The brick-shaft furnace requires no description other than that 
the brick shaft is supported on a heavy cast-iron entablature 
supported on cast-iron columns. 
The all water-jacketed furnace just described measured 50 
inches wide and 132 inches long at the lower jackets, 34 inches 
wide between the noses of the tuyeres. It was nearly 17 feet deep 
from the feed-plate to the bottom of the crucible. 
Since these furnaces have been built, much larger furnaces on 
the same design have been erected at other works, and have given 
the greatest satisfaction ; in fact, it may be safely said that the days 
of the brick furnace are over in all newly erected smelting plants. 
The “ blowing-in” operation, or starting of one of the blast 
furnaces, requires experience, and a sharp eye kept on all that is 
going on. At the risk of being prolix, I will describe the actual 
operation of starting a lead-blast furnace. 
From two to four days before the real start is made, a drying 
warming fire is lighted in the brick crucible. The water-pump is 
started, and water turned on to all the cast-iron and wrought-steel 
jackets, tuyeres, and separator breasts. Usually there is a 
separator at both ends of a large furnace, and when the fire 
is lighted, one of these separators, breast and slag spout, is taken 
out of the furnace to leave an opening through which the wood is 
passed into the crucible. As soon as the bricks of the crucible 
begin to warm up, the engine driving the blower is started (or in 
a nest of furnaces the blast is let into the ‘“ bustle-pipe ” from the 
main blast or air-pipe), and the fire is urged by the wind thus 
forced into the furnace. Care is taken that a plentiful supply of 
water is kept in all the parts of the furnace that would otherwise 
get heated. The 15 tons of lead requisite to fill the crucible is 
now melted in with the aid of the wood fire (urged by the blast 
from the blower) in lots of twenty-five to fifty bars at a time. 
This usually takes eight or twelve hours, and it is not advisable, 
though quite possible, to take less time, inasmuch as the lead 
would not retain sufficient heat to keep it molten for the few 
hours required, after the furnace is closed up or started, before 
the furnace begins itself to produce lead from the ore. Imme- 
diately all the bars of lead are thoroughly melted in, the whole of 
the hot ashes and coals from the wood are then skimmed off the 
lead, leaving it almost quite clean. ‘Too much time must not be 
wasted over this operation, for the molten lead in the crucible is 
cooling while exposed to the air. It is also very necessary to get 
these ashes out, because if left in the furnace they form what is 
called a “crust” over the well or crucible, which acts as a shield, 
and prevents the lead reduced in the smelting operation from 
