be constructed in the middle of the rubbish, or if there is a convenient smooth face on the footwall of a lode, a semicircular wall built against it encloses a space very suitable for the purpose required. The pass may serve also as a climbing way for the men, especially if it is provided with a chain; but it should be used in this manner only for short distances. It is far better to keep the ore-pass distinct from the climbing way, in case any stones should lodge on the sides and fall during the ascent or descent of the men.

A pass is often lined with timber instead of stone, and sometimes it is merely an intermediate shaft or winze set apart as a shoot. At the Van Mine the passes, whether they are small shafts sunk on purpose, or passages reserved in the rubbish used as filling, are 6 feet by 3 feet, within the timber; each pass is divided into two unequal compartments by a partition made of 1-inch plank nailed to cross-timbers called dividings, and the larger one is closely lined with similar planks. This forms the "shoot" proper. The small compartment is provided with ladders and serves as a climbing way, and is also useful in case the larger one should become choked; a board can be taken out from the side at any time, and large stones obstructing the passage can be dislodged with safety. Vertical passes lined with timber sometimes have pieces of steel rail put across at intervals, to break the fall of the "stuff."

The pass is provided at the bottom with a mouth closed by a door of some kind, and when this is opened, the mineral falls out into the waggon which has been brought underneath.

-

II. FLOW ALONG PIPES. This method of transport becomes available when one has to deal with liquid or gaseous minerals, or with solutions, but these cases occur more frequently above than below ground. However, brine is led along wooden launders and pipes in some salt mines. Natural inflammable gas in a few exceptional cases is piped off from a blower and buint for illuminating purposes; this is done at a salt mine at Bex in Switzerland.

III. CARRIAGE BY PERSONS.-The simplest and no doubt the oldest method of transport along underground roads is carriage by persons. It still survives in some places for short distances.

In the Forest of Dean, boys carry iron ore on the back in oval trays, called "billies," from the actual working-place to the nearest barrow-road or waggon-road. The tray is made of wood, with a rim of sheet iron, and is about 6 inches deep, 22 inches in length in the direction of the long axis, and 12 to 15 in the direction of the short one. The load carried in a "billy" varies, according to the nature of the ore and the strength of the lad, from 90 to 112 lbs. or even more. The lad goes on all-fours, using his hands to support himself as he makes his way through

low and tortuous passages. This method of transport is rendered necessary by the nature of the excavations, which are very irreg ular; but the distances along which the ore is carried are small, generally from 30 or 40 to 50 yards, and rarely as much as 100 yards.

The German miner commonly makes use of a tray into which he scrapes his mineral or rubbish with a tool like a hoe, and he then carries his load to the nearest "pass" or to a waggon-road in the immediate neighbourhood.

In the little slate mines near Cochem on the Moselle, men and lads carry up the blocks of slate upon their backs, walking upon steps cut in the rock. They come up with their hands upon the ground, bent almost double under the weight of the block, which rests upon a thick pad. Again, blocks of slate are still carried on the back from the working-place to the waggon-roads in the slate mines of the Ardennes. In the Sicilian sulphur mines the same method is common, and it is also found in some parts of Spain and China, where baskets are used, whilst bags are employed in Mexico and Japan. Indeed, in these cases, as at Cochem, the mineral is not only carried along comparatively level roads but is also brought to the surface.

IV. CONVEYANCE BY SLEDGES.-Sledges, or sleds, enable greater loads to be transported; but they are not available unless the conveyance takes place along roads sloping downwards. They are little employed underground.

V. CONVEYANCE BY VEHICLES WITH WHEELS.— We now come to the methods by which minerals and rubbish are usually transported both above and below ground-viz., by some kind of wheeled vehicle. Here we may at once make two classes. A. Vehicles running upon the ground or on boards; B. vehicles running upon rails.

A. Vehicles Running on the Ground or on Boards.— Wheelbarrow: The simplest wheeled carriage is the barrow. It consists of a body with two handles and one wheel. The barrow used in Cornwall at the present day is not unlike that figured more than three centuries ago by Agricola. It has no legs, but in many ore-mines a barrow with legs is employed, somewhat resembling a navvy's barrow. Mine-barrows are usually made of wood, and have either a wooden or a steel wheel. The Cornish barrow is tipped sideways, whilst the barrow with legs is tipped either sideways or over the end. This latter form of barrow requires a higher and better level; it is a more advantageous appliance, as it throws a greater part of the load on to the wheel and relieves the miner's arms to a certain extent. The barrow often runs along the natural floor of the workingplace or level, but less labour is required if it is provided with a road made of planks or strips of iron.

Carts and Waggons In the low passages, only 18 inches to

20 inches high (Fahrten), leading from the working face of the copper-shale mines at Mansfeld to the main roads, tiny waggons on four wheels are employed.

Carts drawn by horses are used in some large underground quarries.

A mine waggon largely employed in Germany at one time, and still seen occasionally, is the so-called Hungarian "Hund." It has a rectangular body resting upon four wheels, two small in front and two large near the middle; the workman presses down a little handle at the back to make the load rest upon the two big wheels only, and pushes the waggon along a board at the bottom of the level. The Germans have also used four-wheeled waggons running upon two boards; and they were sometimes provided with a projecting pin underneath which kept them upon the track.

B. Vehicles Running upon Rails.-The points to be considerd are (a) the road; (b) the waggons; (c) the power employed for traction.

(a) Railways.-Cast-iron tram-plates were introduced in the last century, and were succeeded by wrought-iron rails; these in their turn are being superseded by rails made of steel. Various forms of rails are in use. The simplest is a bar of iron set on its edge, or a strip of flat iron nailed to longitudinal sleepers. Rails of the former kind are made, for instance, of bars by 21 inches, or by 2 inches, fixed by wooden wedges in slits cut in the sleepers. This rail has the disadvantage of wearing a groove in the flange of the wheel, but it is easily and quickly laid and readily bent into curves. Rails made of bars of round iron are used in some Welsh slate quarries.

FIG. 397.

FIG. 398.

The bridge-rail was in great favour at one time, either laid upon longitudinal or cross sleepers; but nowadays flanged T-headed rails made of steel are preferred. Care should be taken to have strong and well-laid lines, especially where there is likely to be much traffic. In this, as in many other departments of mining, it is very bad economy to cut down the original expenses too much. What is saved on the first cost will be spent over and over again in repairs, to say nothing of the loss of time and money caused by delays in the traffic.

The gauge varies from 14 inches to 3 feet or more; 20 inches to 22 inches is a common gauge in vein mining.

The

weight of the rails for such roads is from 10 to 30 lbs. per yard. Figs. 397 and 398 show the sections adopted respectively by Legrand of Mons and Howard of Bedford, for rails weighing

18 lbs. per yard. The rails may be simply spiked to wooden sleepers, or they may be laid in chairs. In important roads fishplates should be used.

There is a tendency at the present day to adopt steel sleepers, which are supplied by the makers to suit roads of various gauges. They have proved to be very convenient and efficient, and in this country they are cheaper in the end than wood. Among their advantages are exact uniformity of gauge, easy and rapid

FIG. 399.

laying, fewer repairs. They are usually made of rolled steel, and the rails are fixed either by clips, or by clips and keys.

One form of road supplied by Legrand of Mons (Fig. 399), has the clips of one sleeper on the outside of the rail and those of the next on the inside of the rail. The clips are firmly riveted to the sleepers. In constructing the road, the sleepers B are laid at suitable distances apart, exactly parallel to one another; the alternate sleepers A are then put in obliquely, as shown by the dotted lines, and knocked into position with a hammer; the rails are joined by fish-plates.

Howard's sleeper (Fig. 400) is made from a plate of steel rolled with a corrugation; the lips which

FIG. 400.

constitute the chairs for the rails are formed by pressing down this corrugation without cutting away any of the metal. The jointing sleepers have a double corrugation, and the rails are fastened with a simple key which

is serrated on one side. Some of Howard's sleepers for underground work can be used without any keys.

Bagnall's sleeper is also distinguished by longitudinal corrugations which stiffen it and prevent its buckling. The Widnes Chair and Sleeper Company prefer a section like that of a V-shaped trough; they claim that the penetration of this sleeper into the ground ensures great stability.

Where a mine has a stock of old rails or old iron, it is often more economical to convert it into sleepers than to sell it as scrap.

*

There are several methods in use. White of Widnes utilises old bridge rails (Figs. 401 and 401a) by inserting two clips (Figs. 402 and 402a) into a piece of rail cut to the required length; the clip is held in place by a pin which passes into a hole punched FIG. 4014.

FIG. 401.

in the sleeper. At the Llechwedd slate mine in North Wales, two other methods have been devised by Mr. C. Warren Roberts (Figs. 403 and 404) for utilising old channel iron and flat iron. Stamped iron clips are riveted on so as to take the outer side of

the flange of the rail, and similar clips are bolted on against the inner flange. In order to allow for any small irregularity in the width of the flange, the hole for the bolt is made oval, and this enables the clip to be adjusted to the flange exactly.