MINERALS--WELLS.
Dost thou hear the hammer of Thor,
Wielded in his gloves of iron?
As with leather, so with stone, the hand tools and hard labour have not
changed in principle since the ancient days. The hammer for breaking,
the lever for lifting, the saw for cutting, rubbing-stones and irons for
smoothing and polishing, sand and water for the same purpose, the mallet
and chisel, and other implements for ornamenting, the square, the level,
and the plumb for their respective purposes, all are as old as the art
of building.
And as for buildings and sculpture of stone and marble made by hand
tools, we have yet to excel the pyramids, the Parthenon of Athens, which
“Earth proudly wears as the best gem upon her zone,” the palaces,
coliseums, and aqueducts of Rome, the grand and polished tombs of India,
the exquisite halls of the Alhambra, and the Gothic cathedrals.
But the time came when human blood and toil became too dear to be the
possession solely of the rulers and the wealthy, and to be used alone to
perpetuate and commemorate riches, power and glory.
Close on the expansion of men’s minds came the expansion of steam and
the development of modern inventions. The first application of the steam
engine in fields of human labour was the drawing of water from the coal
mines of England; then in drawing the coal itself.
It was only a step for the steam engine into a new field of labour when
General Bentham introduced his system of wood-sawing machinery in 1800;
and from sawing wood to sawing stone was only one more step. We find
that taken in 1803 in Pennsylvania, when Oliver Evans of Philadelphia
drove with a high-pressure steam engine, “twelve saws in heavy frames,
sawing at the rate of one hundred feet of marble in twelve hours.” How
long would it have taken hand sawyers of marble at ancient Paros and
Naxos to have done the same?
_Stone-cutting_ machines of other forms than sawing then followed.
It was desired to divide large blocks generally at the quarries to
facilitate transportation. Machines for this purpose are called
stone-channelling machines. They consist of a gang of chisels bound
together and set on a framework which travels on a track adjacent to the
stone to be cut, and so arranged that the cutters may be set to the
stone at desired angles, moved automatically forward and back in the
grooves they are cutting, be fed in or out, raised or lowered, detached,
and otherwise manipulated in the operation.
Other stone-cutting machines had for their objects the cutting and
moulding the edges of tables, mantels and slabs; and the cutting of
circular and other curved work. In the later style of machine the cutter
fixed on the end of a spindle is guided in the desired directions on the
surface of the stone by a pointer, which, attached to the cutter
spindle, moves in the grooves of a pattern also connected to the
rotating support carrying the cutter.
Other forms of most ingenious stone-dressing and carving machines have
been devised for cutting mouldings, and ornamental figures and devices,
in accordance with a model or pattern fixed to the under side of the
table which carries the stone or marble to be dressed; and in which, by
means of a guide moving in the pattern, the diamond cutter or cutters,
carried in a circular frame above the work and adjusted to its surface,
are moved in the varying directions determined by the pattern. A stream
of water is directed on the stone to clear it of the dust during the
operations. The carving of stone by machinery is now a sister branch of
wood carving. Monuments, ornamentation, and intricate forms of figures
and characters are wrought with great accuracy by cutting and dressing
tools guided by the patterns, or directed by the hand of the operator.
For the dressing of the faces of grindstones, special forms of cutting
machines have been devised.
It was a slow and tedious task to drill holes through stone by hand
tools; and it was indeed a revolution in this branch of the art when
steam engines were employed to rotate a rod armed at its end with
diamond or other cutters against the hardest stone. This mode of
drilling also effected a revolution in the art of blasting. Then,
neither height, nor depth, nor thickness of the stone could prevent the
progress of the drill rod. Tunnels through mountain walls, and wells
through solid quartz are cut to the depth of thousands of feet.
One instance is related of the wonderful efficiency on a smaller scale
of such a machine: The immense columns of the State Capitol at Columbus,
Ohio, were considered too heavy for the foundation on which they rested.
The American Diamond Rock Boring Company of Providence, Rhode Island,
bored out a twenty-four inch core from each of the great pillars, and
thus relieved the danger.
In the most economical and successful stone drills _compressed air_ is
employed as the motive power to drive the drills, which may be used
singly or in gangs, and which may be adjusted against the rock or quarry
in any direction. When in position and ready for work a few moments will
suffice to bore the holes, apply the explosive and blast the ledge. The
cleaning away of submarine ledges in harbours, such as the great work at
Hell Gate in the harbour of New York, has thus been effected.
_Crushing_:--Among the most useful inventions relating to stone working
are machines for crushing stones and ores, and assorting them. The old
way of hammering by hand was first succeeded by powerful stamp hammers
worked by steam. Both methods of course are still followed, but they
demand too great an expenditure of force and time.
About a third of a century ago, Eli Whitney Blake of New Haven,
Connecticut, was a pioneer inventor of a new and most successful type of
stone breaking machine, which ever since has been known as the “Blake
Crusher.” This crusher consists of two ponderous upright jaws, one fixed
and the other movable, between which the stones or ores to be crushed
are fed. Each of the jaws is lined with the hardest kind of chilled
steel. The movable jaw is inclined from its lower end from the fixed jaw
and at its upper end is pivoted to swing on a heavy round iron bar. The
movable jaw is forced toward the fixed jaw by two opposite toggle levers
set, in one form of the crusher, at their inner ends in steel bearings
of a vertical vibrating, rocking lever, one of the toggles bearing at
its outer end against the movable jaw and the outer toggle against a
solid frame-work. The rocking lever is operated through a crank by a
steam engine, and as it is vibrated, the toggle joint forces the lever
end of the movable jaw towards the fixed jaw with immense force,
breaking the hardest stone like an eggshell.
The setting of the movable jaw at an incline enables the large stone to
be first cracked, the movable jaw then opens, and as the stone falls
lower between the more contracted jaws, it is broken finer, until it is
finally crushed or pulverized and falls through at the bottom. The
movable jaw is adjustable and can be set to crush stones to a certain
size.
As the rock drill made a revolution in blasting and tunnelling, so the
Blake crusher revolutionised the art of road making. “Road metal,” as
the supply of broken stones for roads is now called, is the fruit of the
crusher. Hundreds of tons of stone per day can be crushed to just the
size desired, and the machine may be moved from place to place where
most convenient to use.
Other crushers have been invented, formed on the principle of abrasion.
The stones, or ore, fall between two great revolving disks, having
corrugated steel faces, which are set the desired distance apart, and
between which the stones are crushed by the rubbing action. In this
style of machine the principle of a gradual breaking from a coarse to a
finer grade, is maintained by setting the disks farther apart at the
centre where the stone enters, and nearer together at their peripheries
where the broken stone is discharged. Large smooth or corrugated
rollers, conical disks, concentric rollers armed with teeth of varying
sizes, and yet so arranged as to preserve the feature of the narrowing
throat at the bottom or place of discharge, have also been devised and
extensively used.
A long line of inventions has appeared especially adapted to break up
and separate coal into different sizes. To view the various monstrous
heaps of assorted coals at the mouth of a coal mine creates an
impression that some great witch had imposed on a poor victim the
gigantic and seemingly impossible task of breaking and assorting a vast
heap of coal into these separate piles within a certain time--a task
which also seems to have been miraculously and successfully performed
within such an exceedingly short time as to either satisfy or confuse
the presiding evil genius.
Modern civilisation has been developed mostly from steam and coal, and
they have been to each other as strong brothers, growing more and more
mutually dependent to meet the demands made upon them.
The mining of coal, and its subsequent treatment for burning, before the
invention of the steam engine, were long, painful, and laborious tasks,
and the steam engine could never have had its modern wants supplied if
its power had not been used to supplement, with a hundredfold increased
effect, the labour of human hands.
It being impracticable to carry steam or the steam engine to the bottom
of the mine for work there, compressed air is there employed, which is
compressed by a steam engine up at the mouth. By this compressed air
operated in a cylinder to drive a piston, and a connecting rod and a
pick, a massive steel pick attached to the rod may be driven in any
direction against the wall of coal at the rate of from ninety to one
hundred and twenty blows per minute; and at the same time the discharged
compressed, cold, pure, fresh air flows into and through the mine,
affording ventilation when and where most needed.
In addition to these great drills, more recent inventors have brought
out small machines for single operators, worked by the electric motor.
After the coal is lifted out, broken and assorted, it needs to be washed
free of the adhering dust and dirt; and for this purpose machines are
provided, as well as for screening, loading and weighing. The operations
of breaking, assorting and washing are often combined in one machine,
while an intermediate hand process for separating the pieces of slate
from the coal may be employed; but additional automatic means for
separating the coal and slate are provided, consisting in forcing with
great power water through the coal as it falls into a chamber, which
carries the lighter slate to the top of the chamber, where it is at once
drawn off.
The chief of machines with _ores_ is the _ore mill_, which not only
breaks up the ore but grinds or pulverises it.
Some chemical and other processes for reducing ores have been referred
to in the Chapter on Metallurgy.
Other mechanical processes consist of _separators_ of various
descriptions--a prominent one of which acts on the principal of
centrifugal force. The crushed material from a spout being led to the
centre of a rapidly rotating disk is thrown off by centrifugal force;
and as the lighter portions are thrown farther from the disk, and the
heavier portions nearer to the same, the material is automatically
assorted as to size and weight. As the disk revolves these assorted
portions fall through properly graded apertures into separate channels
of a circular trough, from whence they are swept out by brushes secured
to a support revolving with the disk.
Many forms of ore washing machines have been invented to treat the ore
after it has been reduced to powder. These are known by various names,
as jiggers, rifflers, concentrators, washing frames, etc. A stream of
water is directed on, into, and through the mass of pulverised ore and
dirt, the dirt and kindred materials, lighter than the ore, are raised
and floated towards the top of the receptacle and carried away, while
the ore settles.
This operation is frequently carried on in connection with amalgamated
surfaces over which the metal is passed to still further attract and
concentrate the ore. An endless apron travelling over cylinders is
sometimes employed, composed of slats the surface of each of which is
coated with an amalgam, and on this belt the powdered ore is spread
thinly and carried forward. The vibrations of the belt tend to shake and
distribute the ore particles, the amalgam attracts them, the refuse is
thrown off as the belt passes down over the cylinder, while the ore
particles are retained and brushed off into a proper receptacle.
_Amalgamators_ themselves form a large class of inventions. They are
known as electric, lead, mercury, plate, vacuum, vapour, etc.
By the help of these and a vast number of other kindred inventions, the
business of mining in all its branches has been revolutionised and
transformed, even within the last half century. With the vast increase
in the output of coal, and of ores, and the incalculable saving of hand
labour, the number of operators has been increased in the same
proportion, their wages increased, their hours of labour shortened, and
their comforts multiplied in variety and quantity, with a diminished
cost. The whole business of mining has been raised from ceaseless
darkness and drudgery to light and dignity. Opportunity has been created
for miners to become men of standing in the community in which they
live; and means provided for educating their children and for obtaining
comfortable homes adorned with the refinements of civilisation.
_Well boring_ is an ancient art--known to the Egyptians and the Chinese.
Wells were coeval with Abraham when his servant had the celebrated
interview with Rebecca. “Jacob’s well at Sychar--the ancient
Shechim--has been visited by travellers in all ages and has been
minutely described. It is nine feet in diameter and one hundred and five
feet deep, made entirely through rock. When visited by Maundrel it
contained fifteen feet of water.”--_Knight._ Some kind of a drill must
have been used to have cut so great a depth through rock. The Chinese
method of boring wells from time immemorial has been by the use of a
sharp chisel-like piece of hard iron on the end of a heavy iron and wood
frame weighing four or five hundred pounds, lifted by a lever and turned
by a rattan cord operated by hand, and by which wells from fifteen
hundred to eighteen hundred feet in depth and five or six inches in
diameter have been bored.
This method has lately been improved by attaching the chisel part, which
is made very heavy, to a rope of peculiar manufacture, which gives the
chisel a turn as it strikes, combined with an air pump to suck up from
the hole the accumulating dirt and water.
Artesian wells appear to have first been known in Europe in the province
of Artois, France, in the thirteenth century. Hence their name. The
previous state of the art in Egypt, China and elsewhere was not then
known.
Other modern inventions in well-making machinery have consisted in
innumerable devices to supplant manual labour and to meet new
conditions.
_Coal Oil_:--Reichenbach, the German chemist, discovered paraffine.
Young, soon after, in 1850, patented paraffine oil made from coal. These
discoveries, added to the long observed fact of coal oil floating on
streams in Pennsylvania and elsewhere, led to the search for its natural
source. The discovery of the reservoirs of petroleum in Pennsylvania in
1855-1860, and subsequently of gas, which nature had concealed for so
long a time, gave a great impetus to inventions to obtain and control
these riches. With earth-augurs, drills, and drill cleaning and clearing
and “fishing” apparatus, and devices for creating a new flow of oil, and
tubing, new forms of packing, etc., inventors created a new industry.
Colonel E. Drake sank the first oil well in Pennsylvania in 1859. Since
then, 125,000 oil wells have been drilled in that and neighbouring
localities. The world has seldom seen such excitement, except in
California on the discovery of gold, as attended the coal oil discovery.
The first wells sunk gushed thousands of barrels a day. Farmers and
other labouring men went to bed poor and woke up rich. Rocky
wildernesses and barren fields suddenly became Eldorados. The burning
rivers of oil were a reflection of the golden treasures which flowed
into the hands and pockets of thousands as from a perpetual fountain
touched by some great magician’s wand.
Old methods of boring wells were too slow, and although the underlying
principle was the same, the new methods and means invented enabled wells
to be bored with one-tenth the labour, in one-tenth the time, and at
one-tenth the cost. Many great cities and plains and deserts have been
provided with these wells owing to the ease with which they can now be
sunk.
Another ingenious method of sinking wells was invented by Colonel N. W.
Greene at Cortland, New York, in 1862. It became known as the “driven
well,” and consisted of a pointed tube provided with holes above the
pointed end, and an inclosed tube to prevent the passage of sand or
gravel through the holes in the outer tube. When the pointed tube was
driven until water was reached the inner tube was withdrawn and a pump
mechanism inserted. This well, so simple, so cheap and effective, has
been used in all countries by thousands of farmers on dry plains and by
soldiers in many desert lands. With these and modern forms of artesian
wells the deserts have literally been made to blossom as the rose.