capable of accommodating over 100 large steamships, and ships up to 10,000 tons capacity have used the harbour. The seachannel has a depth of 15 to 16 feet at low water, and is capable of being deepened to 20 feet.

The following shews the increase in the coal-shipments :

In addition to coal-shipments there is a considerable importtrade in timber. There is also an extensive shipyard, and five large graving-docks at the port.

The chief improvements at present in progress are the widening of the entrance-channel, by two steam-hopper dredgers, and the reconstruction of the old east pier, by enclosing it in concrete.

SEGHILL COLLIERY.

The output of about 1,580 tons of coal per day is drawn from two shafts.

The colliery is ventilated by an open-running fan, 35 feet in diameter, driven by a Corliss engine with a cylinder 16 inches in diameter by 3 feet stroke, fitted with sugar-tong-clip valve-gear. The engine is controlled by a governor, which varies automatically the cut-off and maintains a regular speed, even when the steam-pressure varies. The speed is readily altered by changing the weights placed on the governor, and this can be easily effected while the engine is running. The results of experiments, at speeds of 40 and 60 revolutions per minute, are recorded in the following table:

A vertical engine, with a cylinder 9 inches in diameter and 9 inches stroke, running at 200 revolutions per minute, drives a dynamo of 15 horsepower. The current is conveyed to a motor of 10 horsepower placed in the Low Main seam, driving a threethrow ram-pump, delivering 100 gallons of water per minute against a vertical head of 120 feet.

The main-and-tail-rope haulage is worked by an horizontal engine, with a cylinder 13 inches in diameter by 30 inches stroke, fitted with valve-gear controlled by a governor, which automatically varies the cut-off and maintains a constant speed. The speed can be varied between 70 and 100 revolutions per minute by altering a spring attached to the governor, and this can be done while the engine is running. When not employed in hauling, the tail-rope drum can be put out of gear, and a clip-wheel put into gear; and the power is then transmitted by means of an endless wire-rope to the main differential ram-pump placed in the Low Main seam, and forces the water to the surface.

Two similar engines work the endless-rope haulage in the Blake and Yard seams, with 10 and 73 miles of rope respectively. The shop-engine has a cylinder 10 inches in diameter and 22 inches stroke.

An engine, with a cylinder 10 inches in diameter and 22 inches stroke, works the screens, including 4 shakers, 4 bar-belts for best coal, 45 feet long, with lowering arms; 2 belts for small coal; 1 duff-coal creeper; 3 tub-creepers; and 4 kick-ups. These are erected in an iron building with H girder steel legs.

All the engines are supplied with steam at a pressure of 100 pounds per square inch, except two old vertical condensing winding-engines, with cylinders 33 and 34 inches in diameter respectively, for which the pressure is reduced to 40 pounds per square inch. All steam is superheated. There is one range of 5 Lancashire boilers, 8 feet in diameter and 30 feet long. The pit and shops are worked by 3 boilers, mechanically fired with smallcoal, mixed with some rough nuts.

The gas-works comprize 9 fire-clay retorts and two gas-holders.

MESSRS. LOCKE BLACKETT AND COMPANY,
LIMITED: LEAD-WORKS.

In producing white-lead by the old Dutch stack-process, the metallic lead is cast into thin plates and placed upon earthenware pots containing dilute acetic acid, which in turn rest upon a layer of spent oak-bark; boards are placed above the lead, and other layers of bark, pots, lead and boards, are placed in the stacks until the stacks are full. After a period of about 3 months, the material is removed from the stacks, and a considerable proportion of the metallic lead is found to have been converted into hydrated carbonate of lead. This is crushed, washed, ground and dried, and then becomes the "genuine dry white-lead" of commerce. For painters' requirements, it is ground in refined linseed oil.

CONSETT IRON-WORKS, CONSETT.

COAL AND COKE.

The Consett Iron Company, Limited, at the present time, own eleven collieries, extending over an area of 13,000 acres, and producing annually about 1,500,000 tons of coal. There are about 1,050 coke-ovens, producing about 600,000 tons of coke per annum. The greater proportion of the coke is consumed at the company's blast-furnaces, and the remainder is sold for use in blast-furnaces, etc., in Cumberland, Cleveland, and foreign pigiron producing districts.

PIG-IRON.

Blast-furnaces.-The 7 blast-furnaces are each 55 feet high, with a hearth 9 feet in diameter; height to top of bosh, 20 feet; diameter of the bosh, 20 feet; diameter of the throat, 14 feet; and a bell with an opening of 10 feet. There are seven tuyeres to each furnace. All the furnaces are fed with material by means of a bell and hopper, with a standard beam and hydraulic brake. The ore and other material for the furnaces is conveyed on a high-level approach, considerably above the tops of the furnaces, in bottom-door trucks, and is tipped from these into depôts, from which the charging barrows are filled.

Each of the furnaces is equipped with three Cowper stoves, varying from 65 to 90 feet in height, and from 21 to 24 feet in diameter.

The pressure of blast, now maintained, is 5 pounds per square inch, and its temperature on entering the furnace is about 1,200° Fahr. At the present time, six furnaces are in blast, and the seventh one is being relined. The six furnaces are making Bessemer pig-iron from imported Spanish and other ores, and produce on an average 750 tons per furnace per week. The limestone comes from the Consett Iron Company's quarries at Stanhope-in-Weardale.

The blowing engines are either of the beam or the vertical tandem type. There are six beam-engines, and two, being obsolete, will shortly be removed. The remaining four engines of this class have steam-cylinders, 50 inches in diameter; and blowing-cylinders, 100 inches in diameter, by 9 feet stroke, designed for a blast-pressure of 5 pounds per square inch. The two vertical tandem engines have steam-cylinders 50 inches in diameter; and blowing-cylinders, 100 inches in diameter, by 5 feet stroke, designed for a working pressure of 10 pounds, and in case of emergency will work to 15 pounds per square inch. They are fitted with Wheelock steam-valve gear and Adamson expansion-governors.

The steam required for driving the blowing-engines, etc., is raised in 19 double egg-ended boilers, each consisting of two lengths, 35 feet long by 4 feet in diameter; and 12 double tubular boilers, each 313 feet long, six of which are 7 feet in diameter, and the remainder 7 feet in diameter. At the present time, three blocks of two boilers are being erected, each of the Babcock-Wilcox water-tube type, capable of working to a pressure of 160 pounds per square inch. The waste-gases from the stoves and boilers pass through a large underground flue to a fire-brick chimney, 250 feet high and 16 feet in internal diameter, at the top.

The slag from the furnaces is removed in side-tipping ladles, with a capacity of 10 tons.

Engines and Brush dynamos, which generate the energy for lighting the works, are placed in Nos. 1 and 4 blowing-engine houses.

STEEL PLATES.

There are two melting-shops supplying ingots for the manufacture of steel plates. In the east shop, there is a range of nine Siemens open-hearth furnaces, six of 35 tons capacity, and

three of 28 tons. In the west shop, there are eleven similar furnaces, nine of 20 tons capacity, one of 28 tons and one of 35 tons. These furnaces are supplied with gas from a range of 33 steam-blown Siemens gas-producers. The two melting-shops produce about 4,200 tons of ingots per week.

The No. 2 cogging-mill is a 28 inches mill, driven from the No. 2 plate-mill engine, through steel bevel-gearing, and is reversed by means of a steam-clutch. The mill consists of one stand each of pinions and rolls, fitted with the usual live-roller frames, and screwing and edging gear. Cutting is done by means of a steam-hammer placed at right angles to the mill, and served by a steam jib-crane. This mill is capable of dealing with about 1,650 tons of ingots per week.

The No. 1 plate-mill has one stand of pinions, one stand of roughing rolls, and one stand of finishing rolls, each 6 feet long by 25 inches in diameter, driven by a high-pressure, direct-acting, non-condensing engine, with a fly-wheel weighing 70 tons. The steam-lift is capable of handling slabs weighing from 20 to 25 cwts. The capacity of the mill is equal to 400 tons of plates per week.

The No. 2 plate-mill is a clutch-reversing mill, and contains one stand of pinions, one stand of roughing rolls, and one stand of finishing rolls, each 7 feet long by 25 inches in diameter. The mill is driven by a high-pressure, direct-acting, non-condensing fly-wheel engine; and the reverse action is obtained by the fivewheel method and a clutch-motion. All the wheels, shafts and clutches are made of Siemens steel. The output of No. 2 mill is about 800 tons of plates per week.

Each of the preceding plate-mills has plate and scrap-shearing machines conveniently placed for its use. There are 6 Lancashire, 2 Babcock-Wilcox boilers, and 15 furnace-stack boilers, making a total of 23 boilers for driving these mills.

The No. 4 cogging-mill is a 45 inches mill, having one stand of pinions and one stand of cogging rolls, driven by an engine with a pair of coupled high-pressure, non-condensing, directacting cylinders, geared at 21 to 1, the wheels, shafts and couplings all being made of Siemens mild steel. The mill is provided with live-roller gear on each side, and hydraulic edging gear on the delivery side. The top roll is balanced by hydraulic, and the screwing is effected by steam-power. In a line with the mill,