Quarrying

“ This system of construction is very wasteful of materials, and can only be resorted to where extensive quarries close at hand are able to furnish readily and cheaply very large quantities of stone, especially where, as at Portland and Table Bay, convict labour has been advantageously utilized in quarrying. ”

“ The number of men generally employed in quarrying it is about four hundred; their wages from twelve to eighteen shillings per week, varying with the quantity raised. The lord of the soil receives one halfpenny a foot for all that is quarried; the freight during war was as high as 25 shillings per ton, at present it is only 16s. Fourteen cubic feet weigh one ton. The weight of the blocks generally varies, from five cwt. ”

“ Accordingly, the first thing the next morning they got out the hammer and drills, dynamite, caps and fuse, and became stone quarriers, setting themselves the task of driving a “discovery” tunnel on the vein, because it was easier to tunnel than to sink a shaft. Being new to the quarrying trade, they made slow work of it, blistering their hands plentifully the first day or two, and learning only by laborious experience in drilling the hard rock how to place their blasts where they would do the most good. ”

“ Perhaps quarrying would be a better term than mining in this case, as Edison's plan was to approach the rock and tear it down bodily. The faith that "moves mountains" had a new opportunity. In work of this nature it had been customary, as above stated, to depend upon a high explosive, such as dynamite, to shatter and break the ore to lumps of one hundred pounds or less. ”

“ Granite, having little grain, can be cut into blocks of almost any size and shape. Specimens as much as eighty feet long have been taken out and transported great distances. The quarrying is done by drilling a series of small holes, six inches or more deep and almost the same distance apart, inserting steel wedges along the whole line and then tapping each gently with a hammer in succession, in order that the strain may be evenly distributed. ”

“ Our first excursion will be to a locality where an open cut has been made for the purpose of carrying on quarrying operations. The accompanying photograph has been so taken as to include both the top and the bottom of the quarry (Fig. 1) . Let us first inspect the rock in the lower part of the quarry. The existence of planes of fracture, or joints, crossing the rock in various directions, dividing it into blocks, early attracts our attention. ”

“ Many building and manufacturing enterprises have met disastrous checks, because of a tendency to assume availability of stone without making the fullest technical investigation. Many quarrying ventures have come to grief for the same reason. It is easy to assume that, because a granite in a certain locality is profitably quarried and used, some other granite in the same locality has equal chances. However, minor differences in structure, texture, and composition, or in costs of quarrying and transportation, may make all the difference between profit and loss. ”

“ Quarrying Quartz.—The quarrying of quartz rock differs little from the quarrying of other metalliferous vein-stones. The lode descends steeply, and the excavation must follow its course. Sometimes the quartz is so soft that it may easily be loosened with the pick. The harder rock is blasted. Soft quartz is that which is penetrated by numerous cavities, though the lumps between the cavities may be very hard. ”

“ Speaking broadly, all methods of mining come under the head of either open working or closed working. Open working is employed when the deposits have no overburden of barren rock or earth, or where this overburden is of such small depth that it can be easily and cheaply removed, leaving the coal deposit exposed. The mining of such exposed seams of coal is really a process of excavation or quarrying, and the machines used in making open-pit excavations and in quarrying are applicable to the work. ”

“ This quality renders it unsuitable to many quarrying operations. In certain kinds of weak rock, its disruptive effects are inferior to those produced by gunpowder. But in ordinary mining operations, where strong tough rock has to be dealt with, its superior strength and quickness of action, particularly the latter quality, produce much greater disruptive effect than can be obtained from gunpowder. Moreover, its shattering action tends to break up into small pieces the rock dislodged, whereby its removal is greatly facilitated. ”

“ A part of Jim's day's work, after his letters were answered and written in the morning, was to tramp over every portion of the job. The quarry, in the mountain to the north of the dam whence were being taken the giant rock for embedding in the concrete was his first care. The stone must be of the right quality and of proper weight and contour to bind well with the cement. The quarrying itself must be going forward rapidly and without waste. Then came the giant sand dump, where the dinkies had filled a canyon with the sand from the river bed. ”

“ It is a method used more frequently in quarrying than in trench excavation 264where it is not necessary to preserve the stone intact. In blasting, a hole is drilled in the rock, and is loaded with an explosive which when fired shatters the rock and loosens it from its position. ”

“ It is most probable that the materials would be rough unhewn surface stones, for powder to blast out more solid material would be expensive. Tools for quarrying would be unattainable, and men with skill or industry to work them even still more so, while ant-hill clay would be the only available cement, unless the erection should be in a limestone district, or near a beach, where shells in abundance could be procured and burnt into lime. ”

“ In most places the quarrying of the Royal stratum appears to have been prosecuted as far as was intended, and the stones were all removed, but in one place, at least, the work was for same reason left unfinished. Some of the ashlars were only outlined and some partially cut out, the great stones still remaining in their original places. ”

“ In almost every kind of work new methods are invented after a while. In quarrying, however, the same old methods are in use. The only difference is that, instead of the work being done by muscle, it is [Pg 15] done by compressed air or steam or electricity. Compressed air or steam works the drill and the sledgehammer. The drill is held by an arm, but the arm is a long steel rod which is only guided by the workman. Not the horse-sweep of old times, but the steam derrick and the electric hoist lift the heavy blocks from the quarry. ”

“ The closed joints or incipient joints cause planes of weakness, known variously as rift, grain, etc., which largely determine the shapes of the blocks which may be extracted from a quarry. Where properly distributed, they may facilitate the quarrying of the stone. In other cases they may be injurious, in that they limit the size of the blocks which can be extracted and afford channels for weathering agents. Some rocks of otherwise good qualities are so cut by joints that they are useless for anything but crushed stone. ”

“ They are of prime importance from an industrial point of view, seeing that the art of quarrying consists mainly in detecting and making proper use of them. Their abundance in all kinds of rocks, from those of recent date up to those of the highest antiquity, affords a remarkable testimony to the strains which the terrestrial crust has suffered. They have arisen sometimes from tension, such as that caused by contraction from the drying and consolidation of an aqueous sediment or from the cooling of a molten mass ”

“ The mining industries are limited to the quarrying of buildingstone and granite, besides soapstone and talc and magnetite ores, together with a considerable yield from the brick and tile yards and from the beds of Portland cement. ”

“ Ruth. The factory.
(She gulps as if taking poison. Guy drinks his glass off and goes to door.)
CURTAIN.
ACT III
A rough road terminates in the quarry whose hewn crags rise high at the right. Below them, behind the road is an old shed of planks, open to the front. To the left, the quarrying has caused a steep dip. The road ends, the rock descends to it and beyond, so that the opposite side of the valley below is visible, seen dimly in the night. Gorse and heather grow over the deserted workings. There is no moon, but the lighting is sufficiently strong for faces to be seen. ”

“ To hasten disintegration, water was often applied to the heated rock, the loosened portion being afterwards removed by pick or hammer and wedge. In modern times blasting has become a necessity for the excavation of rock and other hard material, as in open surface cuts, quarrying, tunnelling, shaft-sinking and mining operations in general. ”

“ It is quarrying rather than mining. Add to this that the reefs which were originally worked as outcrops have now been traced to enormous depths, and present the same features as those at the surface. A conservative estimate of the value of the gold has placed it at seven hundred millions of pounds. ”

“ Other similar quarries of more than local fame were situated round Horsham in Sussex, [255] and Horsham slates continued in demand from early days until the diminished solidity of house construction made a less weighty, and incidentally less picturesque, material requisite for roofing.
The work of quarrying stone counted as unskilled labour, and the rate of pay of quarriers is almost always that of the ordinary labourer. At Martinstow in 1296, men 'breaking stone in the quarry' received 11⁄2d. to 2d. a day, and women, always [83] the cheapest form of labour, 1d. ”

“ A colony of substantial three-room houses, two large boarding-houses, a power house and, farther up beyond the pines, a stone house and a long low building, partly of wood, partly of granite waste cemented, circled the edges of the quarry.
The usual tale of workmen in the fat years was five hundred quarrymen and three hundred stone-cutters. This population of working-men, swelled to three thousand by the addition of their families, increased or diminished according as the years and seasons proved fat or lean. ”

“ The work at the rock quarry was organized according to the same futilitarian pattern that governed the manure-pile operation. Rock had to be hacked, pried and blasted from one end of the quarry, then reduced to coarse gravel with sledge-hammers and carted to the other end of the excavation in wheelbarrows. Most of the men commenced working at some task in the quarry with the automatic unconcern of trained beasts who have paused for rest and water, perhaps, but have never fully stopped. ”

“ For their jewels will be unfolding presently, to soften the cleft granite with misty green and bring the vernal time to these silent cliffs.
The quarry lies like a gash in the slope of the hills. To the dizzy edges of it creep heather and the bracken; beneath, upon its precipices, a stout rowan or two rises, and everywhere Nature has fought and laboured to hide this wound driven so deep into her mountain-side by man. A cicatrix of moss and fern and many grasses conceal the scars of pick and gunpowder; time has weathered the harsh edges of the riven stone ”

“ A quarry should, if possible, be opened on a hillside, for in this ease it is usually much easier to dispose of the water which necessarily collects in any deep excavation, and which, if drainage by gravity is not afforded, must be removed by pumping, at considerable expense. As it is generally most convenient to operate on a vertical face of rock, the preliminary work of opening Va quarry is usually directed toward the production of this result ”

“ This quarry, and one at a short distance, merely supply the blocks of granite, which, being detached from the main stone, are piled upon cars, and sent down an inclined plane to the rail-road, by means of a powerful chain, which acts at once as a support and check, suffering the load to proceed slowly down the declivity, and at the same time sending up from the bottom, upon another track, the empty car from which the granite has been unloaded below, as the buckets of a well are drawn up and down. ”

“ If dimension stone is required, a deep horizontal groove is cut near the top or the bottom of the bed. The quarry face is then divided into blocks by saw-cuts, channels, or rows of drill-holes, and the blocks are separated by wedging or blasting. As the excavation or stoping progresses, portions of the rock are left in place as pillars to support the roof. At many localities in Europe where roofing slate is quarried, it is found in beds dipping more or less from the horizontal. ”

“ The quarry is full of noises—the clank of the pumps, the rattle of the trucks, the hiss of pneumatic and steam drills, the clink of tampers and the rumble and rattle of the great rocks dislodged by crowbars from the cliffs. Men shout, too, and their voices are as the drone of little gnats; but sometimes, at the hour of blasting, an immense volume of sound is liberated, and the thunder of the explosion crashes round and round the cup and wakes a war of echoes thrown from cliff to cliff. ”

“ In the foreground is a rocky platform on which two men are driving wedges into the rock with hammers with long pliant handles. Others are working with smaller hammers, and one, with a lantern fastened to his cap, is mounting to the platform by a ladder. Above them another man is ascending in the same way to a higher part of the quarry, while from an opening on the right a miner is pushing a truck full of ore along a wooden bridge, and another, down below, is raking the stone into a tray. ”