METALLURGICAL METHODS AT BROKEN HILL. 285 
all. The jackets are supported by lugs, which are riveted on them, 
standing on an oblong frame-work of 8-inch “I” iron, the corners of 
which rest on four hollow cast-iron columns or pillars, serving also as 
waste water-pipes. The jackets are surrounded with an iron strap, 
making the whole a stiff and strong job. The structure at this 
stage, and before the lower jackets are put in place on the brick 
crucible, presents the appearance of a large rectangular box with 
rounded corners, not having any bottom or top, standing on four 
legs—the columns. 
The lower half of the furnace consists of twenty cast-iron hollow 
jackets, each 20 inches in width by 57 inches long. There are six 
jackets on each side, with a circular opening cast in them large 
enough to allow a water-jacketed tuyere to be entered, and these 
tuyeres project beyond the jackets into the furnace some 9 inches. 
Four corner jackets have no tuyere openings, and four end jackets 
(two each end) have 4-inch openings in them to admit air, but no 
water-jacketed tuyere. 
The water is fed into the top of each of these jackets, and is 
conducted to the bottom by a passage cast inside the jacket. The 
escape is from the top, and by having a pipe, bent somewhat to 
the shape of the letter S, the delivery of the water is effected into 
a launder at a point 9 inches above the highest point of the jacket, 
doing away with any chance of steam gathering in it. The launder 
can thus be made a fixture, and does not require to be moved 
when a jacket has to be taken out of a furnace, as in the old style 
of furnace. 
All the water from the top and bottom jackets, tuyeres, breasts, 
separators, and slag spouts delivers into the launder which sur- 
rounds the furnace, and this in its turn empties the water into the 
hollow columns which support the top jackets. From these 
columns pipes underground carry the water to cooling tanks, from 
whence it is pumped back to the supply tank for use again. Each 
of the lower jackets have three lugs for bolts on each outside 
perpendicular edge, and, in addition to bolting the whole of them 
together, a binder of 60 lb. steel rails goes around them to stiffen 
the structure. 
The crucible on which these jackets stand consists of a large pan 
made of 3-inch wrought-iron plate, in which brick is laid with fire- 
clay to form a basin or well to collect the lead reduced from the 
ore. The lead is drawn off from this well by a passage in the 
brickwork, starting at the bottom of the well and passing up and 
outwards at an angle. This system has been incorrectly styled a 
‘siphon tap,” or the ‘‘ Arent’s siphon” after the first user of it, 
but it is plain that it is not a siphon, the lead simply rising in the 
passage and obeying the law of all liquids in finding its level. 
The Matthewson matte separator is an ingenious arrangement, 
which takes advantage of the presence of the blast in the furnace 
