by Andrew Millar, 1916
WHEN I undertook to write a short book on wheat, its habitat, its transportation,
and the production from it of wheaten flour, I set two objects before me.
The first was to tell in simple language, with as few technicalities as
possible, whence and how the raw material is obtained and to describe the
modern method of producing flour, so that my work might be of interest to
all classes of readers. The manufacture of flour is now such a science,
that technicalities cannot altogether be avoided in dealing with the subject;
but I have tried to simplify the terms so that those who know little, or
nothing, of the industry may be easily able to understand the various process
through which the grain passes before pure flour is ready for the use of
the housewife or baker.
We read so much of the wheat fields of the United States and Canada, as
also of those of India, Australia, and Argentina, that more people will
be surprised to learn that more than half of the world's wheat crop is still
grown in Europe.
My second object has been to write a book so technically correct that it
shall be both interesting and useful to millers and all others connected
with the bread stuffs industry. How far I have succeeded, I must leave to
the judgment of my readers.
Flour milling is, even yet, in such a state of transition, and new methods
and machines are so continually being introduced by milling engineers and
their experts, that only by the constant study of the trade journals can
millers keep themselves well informed of the latest innovation in the process
When man first discovered the art of reducing, or grinding, wheat into
meal is, like the origin of the cereal itself, quite unknown; but the oldest
pictorial and other records that are discovered from time to time indicate
that the art, in a crude form, was practiced by the nations of antiquity.
Probably the earliest method was to pound the grain with a stone; and later
a hollow stone was used as a base, and the grain pounded with a pointed
stone, on the pestle and mortar system. There is evidence of this simple
method being used by the Romans as late as A.D. 79. Milling is so often
mentioned in the Bible, and so important was the means of reducing flour
to meal considered, that the Mosaic law forbade anyone to take a millstone
in pledge. The Jews certainly used two round stones, or a guern,
to grind their grain, one stone being made to revolve upon the other. The
earliest authentic history of milling was in Abraham's time, when he told
Sarah to prepare fine meal for the angels, though it is apparent that is
was, even then, an old art, and the grinding of grain was part of woman's
daily work. Presumably Sarah used some sort of a sieve to make the fine
meal from the ordinary meal, and we are told in the Bible of flour, fine
flour, and the finest wheat flour, so that there were, apparently, sifting
appliances and grades of flour even in those days, and the finest flour
was doubtless reserved for the head of the family and honored guests, while
the servants and slaves used the coarse meal.
Egyptians doubtless advanced the art of milling, for their civilization
was far ahead of that of any other country of the ancient world. In hieroglyphics,
on stone, are to be found representations of grinding grain, and sifting
the flour from the husk, or bran, with hand sieves. When the Israelites
fled from Egypt, they doubtless carried their mills with them, as well as
the kneading troughs, which are mentioned in Exodus. Manna had to be ground,
for it states in Numbers xi, 8: "The people went about, and gathered
it, and ground it in mills, or beat it in a mortar, and baked it in pans
and made cakes of it." The art of grinding seems to have come only
from the East, as there had never been found amongst the Aborigines of Australasia
any trace of a grinding device. Neither is there any evidence of the American
Indian having had any idea of grinding Indian corn. The quern, or
hand mill, was introduced into Europe at an early date, for there is evidence
that Gauls and Early Britons used them before the Roman invasion. This style
of milling is estimated to have been in use for at least 4,000 years. Evidently
there were inventors even in those days who tried to provide a better means
of milling than the quern afforded, and a sketch of a statuette in
limestone in the Cairo Museum shows a woman grinding with a roller mill
over 5,000 years ago. Such a mill was recently found in the priest's house
connected with the temple of the tomb of the fifth dynasty Pharaoh, Nefer-Ar-Ka-Ra
(according to Professor Flinders Petrie about 3660-3680 B.C.) at Abusir.
It is of red sandstone, and is now in the Berlin Museum.
Unfortunately the upper stone is missing; but it appears to have been a
kind of roller between which, and the smooth surface, the corn was ground,
and the meal would probably be pushed into a receptacle at the end. There
are two shallow half moon shaped recesses on either side of the plain surface,
and these may also have been intended to receive the meal, or maybe they
were for the knees of the operator to rest in.
Following the quern, the slave and the cattle driven mills made their
appearance. These, with continuously running stones, were probably the direct
parents of the millstone, as it was known up to late in the nineteenth century,
and as, indeed, it is still used for other purposes than wheat grinding.
The Greeks seem to have been the inventors of power driven corn mills, and
the water mill. The water mill, such as it was, appears to have been a kind
of boat anchored out in the stream, the water wheel being pushed round by
the natural flow of the water, and probably the stone ran very slowly. The
Romans improved on this, and probably constructed the first mill dams, to
obtain a head of water at one point; but there seems to be no record of
the date of this invention.
Public water mills are mentioned in the Roman laws of 398 B.C., but it is
questionable if there were many of them at that date; and there is no evidence
of power driven sifting machines. These water wheel mills were introduced
into Britain by the Romans, and doubtless one was erected at each of the
Roman camps. It does not appear that anyone though of building a large water
wheel to drive several pairs of stones till late in the eighteenth century.
In Doomsday Book hundreds of mills are mentioned, and were obviously considered
to be of great value to the owner. There were very stringent laws, about
that time, compelling the people to have their corn ground only at the mill
of the lord of the manor.
The Dutch probably built the first wind mills, and this is easily understood
when it is remembered that there are few rivers in Holland, and that the
country is flat, giving small fall to the rivers. It was largely owing to
the latter reason that wind mills were originally so common in the fen country
on the English East Coast.
John Smeaton, a famous old Yorkshire millwright, introduced many improvements
in mill gearing and driving. It was in a mill near Wakefield that he first
introduced spur gearing, under the millstones, to drive several pairs at
once from the one large spur wheel - an entirely new application of this
simple device. He was also the first to advocate the use of a steam engine
to drive flour mills, in a letter dated 23rd November, 1780, addressed to
the British Government.
The Albion Mills, London, situated near Blackfriars Bridge, are supposed
to have been the first steam mills erected. Built in 1788, they were destroyed
by fire a few years later. They were looked upon as a monopoly, dangerous
to the public interest; but it is said that they reduced the price of flour
in London. Cast iron instead of wood. Wooden shafts, both horizontal and
vertical, are still to be found in the old country mills, looking like revolving
trunks of forest trees.
Millstones, as used for wheat grinding up to the latter part of the nineteenth
century, had changed little since the third century. The upper, or runner,
stone of the pair, carried on the vertical spindle, was made to rotate over
the lower, or bed stone. The wheat was fed into a hole in the center of
the runner and carried through between the stones by centrifugal force,
assisted by the furrows cut in the faces of the stones. IT was ground on
its way to the periphery, and there discharged and collected. The stone
used was French Burr from quarries in Champagne, France. The name of the
man who invented furrows is lost in antiquity; but some sort of dress must
have been invented as soon as stones were driven mechanically, and so ran
more or less continuously.
To all practical purposes the millstones is out of use today, as far as
wheaten flour manufacture is concerned; but it is still largely used for
grinding maize, barley,. and other grains, as well as minerals and other
In the days of the stone mill mechanical sifters were utilized for separating
the bran or husk from the flour. One of the best known at one time was a
wire covered cylinder, set at an angle of 45 degrees. Inside the cylinder,
and fixed to a revolving shaft, were four brushes, each the length of the
cylinder. The meal was collected from the stones in sacks and allowed to
stand for perhaps a few days. It was then fed into the top end of the cylinder,
and the revolving brushes forced the flour through the wire mesh with which
the machine was covered. This machine was called a "bolter," and
hence we got the word "bolt" flour, which was used up to quite
a recent time when the term to "dress" flour became usual; and
modern flour sifters are collectively spoken of as dressing machines here,
though in America the old English name of bolter is still in common use.
Following the wire covered bolter came a textile covered machine, invented
by Blackmore, and called Blackmore's bolting reel. This was a hexagonal
shaped reel, covered with a woven worsted cloth, and can be found still
in many country mills. No force was used inside the reel, the flour being
sifted through the cloth by the shaking action of the revolving reel.
The old wire bolter may be said to have held the field till the introduction
of silk bolting cloth from the continent, about the middle of the nineteenth
century. Long hexagonal reels were than invented, and on the arms forming
the reel the silk was laced tightly.
This silk bolting cloth is woven one meter wide, and since it came into
general use, all mill dressing reels have been built so many meters long,
so that none of the silk might be cut to waste.
Machines of this class are still spoken of by the number of sheets of silk
that are required to clothe them from end to end. The old hexagonal reel
was made six or eight sheets long; and, as the mesh of the silk was much
finer than the old woven wire, the dressing of the flour, i.e., the
separating of the flour from the bran, was done much more perfectly. Silk
has never been superseded by any other material for sifting in modern flour
Sir William Fairbairn was the man who, perhaps more than any other, left
his mark on flour mills of the old type. He brought millwright work to a
high state of perfection. His millstone fittings, gearing, etc., were far
in advance of anything that had previously been seen in any corn mills.
He was responsible for the marvelous improvements that, starting earlier
in the century, had removed so much of the heavy, cumbersome gearing and
shafting from British mills, and replaced it with well designed and balanced
appliances for transmitting power. Others, of course, followed his example,
so that the latter mills of the stone period were triumphs of engineering
skill. The final revolution in flour milling in England really began in
1881. Flour superior to the home made article was being poured into the
country from Hungary and America. British millers began to feel that something
was wrong. The talk was of rollers, and the trade papers were full of the
subject. Improved dress for millstones was advocated, and tried. Diamond
stone dressing machines were introduced. Some few millers had been looking
into the matter; but 99 per cent, believed that only stones could grind
wheat properly, in spite of the fact that Hungarian flour, which was capturing
the best trade, was made on rollers. A few smooth rollers were introduced
to soften middlings, which had hitherto been reduced on stones, or sold
for making ships biscuits and things of that class. Purifiers were invented
to extract the bran particles from the middlings, to enable them to be ground
to better advantage on either stones or rollers.
All this was so much time and money wasted; and yet, perhaps, not totally
wasted, for all the intermediate systems were part of the evolution that
led to the roller mills of today. The first roller mills appeared crude
now to those who remember them. They were not automatic. Partly finished
products were sacked off, and shot on the other machines to be finished,
The year 1881 will always be remembered in the trade as that of the great
exhibition of improved milling machinery which was held in London. A number
of complete mills were erected, and shown at work, in the Agricultural Hall
at Islington. Even then, so great was the difference of pinion as to the
advantage of rollers, that stone mill builders exhibited stones and stone
dressing with which they undertook to extinguish the hopes of the roller
mill men. The millstone, however, as a flour maker, had had its day, and
had to give way to fluted iron rollers; and the roller system came like
an avalanche and swept all the old methods away. At one time in the "eighties
millers seemed to care less about the cost of a roller plant than the speed
with which it could be installed, as their competitors who had changed their
system, before them were carrying off all the trade. The country was at
the same time being inundated with flour from America, whose millers said,
and thought, they were going to capture the trade and put British mills
out of use.
The decrease in the imports of American flour of late years, and the success
of roller milling, shows how the British millers fought, and defeated, the
attempt to put them out of business.
The full history of the evolution in the manufacturing side of flour milling
during the last fifty years would require several large volumes to record
it; so it must suffice to say that the essential differences between the
old and new method were the introduction of the middlings purifier, and
the substitution of iron rollers for stones. The dressing system is much
the same in principle, though improved in detail. Milling is first and foremost,
grinding. With stones the grinding was done with one operation: with rollers
it is a system of graduated reduction.
Though the millstone has practically gone out of use grinding wheat,
yet it is still so largely used for other branches of milling that it is
worthy of consideration in connection with the craft. It is generally used
for making whole wheat meal for brown bread. It is largely employed in Scotch
oat meal manufacture, and for grinding barley, maize, beans peas, and other
provender cereals into meal.
French Stones. - Wheat and maize are always ground on French burr
stones. These burrs, which come in comparatively small pieces from France,
are faced up, fitted and cemented together, and then hooped with two strong
iron hoops to make up the complete stone. The face is dressed down to a
perfect plane. The back, which has purposely been left rough, is covered
with cement to any desired thickness, and rounded towards the center. Each
stone of a pair has a hole in the center, called the eye. The eye of the
runner, 10 inches in diameter, while that of the stationary, or bed stone
is usually 10 inches square. Otherwise the two stones are identical.
The bed stone is laid on its back in a frame, called the hurst, and an iron
plate carrying adjustable brass bearings is firmly fixed in the eye below
the level of the face. A spindle runs up through the eye plate to a required
height; its other end resting to a support below in such a way that it can
be raised or lowered. On the top of the spindle is placed a driving iron,
with two or three projectors which fit in sockets cut in the edge of the
eye of the runner, or revolving, stone. When the stones are face to face,
ready to start grinding, all the weight of the top stone rests on the driving
irons, and so on the top spindle. The spindle is driven from below either
by means of gear wheels or by pulleys and belt. The stones are enclosed
in a circular wooden casing called the hoop, which has a hole in the center
corresponding to the eye of the stone. Over this is mounted a small hopper,
the bottom of which is loose and called the shoe. A rod, called the damsel,
coming up from the spindle and revolving with it, has cams which strike
the shoe and vibrate it, causing a stream of grain to flow into the eye
of the stones. Millstones are usually 4 foot or 4 foot 6 inches in diameter,
and about a foot in thickness.
A 4 foot 6 inch stone runs at a speed of about 130 revolutions a minute,
and a 4 foot stone at 140 to 150 revolutions.
The runner is accurately balanced on the top of the spindle to ensure even
grinding. the wooden casing is far enough from the stone to give good clearance
all round. A sweeper, attached to the periphery of the runner, carries the
meal round with it, till it reaches an opening for its discharge in the
case or frame.
Smooth stones would be of very little use for grinding, so various work
has to be done on their faces to keep them rough, or, technically, sharp.
This is spoken of as dressing the stones. The chief dress is the furrows;
these are cut not redating from the eye, but each of the masters, or long
furrows, is cut from a point 4 inches or 5 inches wide of the center of
the eye, of the stone.
It is immaterial whether a stone runs with, or against, the sun, but, if
against the sun, or left handed, the master furrows lead from the other
side of the eye. The face of the stone had two or three short furrows parallel
to each master furrow, forming a "harp." Furrows are cut about
a quarter of an inch deep at one edge, and taper away to nothing on the
other. they may be 1 1/4 inch wide, and have 2 inches of "land"
between them; but there is no rule, most millers having opinions of their
own on this point. A 4 foot 6 inch stone has about ten master furrows, with
three shorter furrows to each to form the harp.
The face of the stone is kept perfectly flat for about 8 inches from the
extreme edges; from there it should taper slightly towards the eye to such
a degree that, when the two stones, laid face to face, touch at the periphery,
there should be nearly enough space between them at the eye to admit a grain
of wheat. The outer 8 inches of the face has small lines, called "cracks,"
cut in the lands. These should be cut, in clear and sharp, without breaking
the face of the stone between them. To do this correctly on wheat stones
was a sign of the highest skill in the old stone dressers art. These men
boasted how many "cracks" to the inch they could put in. About
twelve was the normal number, and a sharp mill bill, or pick, was necessary
for the work. All the dressing is done with these tools, the workman sitting
on the stone and resting his elbows on a cushion generally stuffed with
bran. Only the best of steel will stand the work, and the tool has to be
continually sharpened. The old stone dresser has almost passed away, and
it is hard to find a miller now who really understands the job, and can
The Derbyshire Peak millstone is of much rougher texture than the French,
and is chiefly used for provender work. It is furrowed, and dressed, and
worked in the same manner as the French stone, but is quarried all in one
piece and cut into shape. It is customary to shrink a couple of lion hoops
on the runner for the sake of safety, in case it should split at work, but
this is not absolutely necessary, and many millers run them unhoopped.
When a pair of millstones of any sort have to be dressed, the runner is
turned over on its back, and the faces of both stones are dressed in exactly
the dame way, so that, when they are grinding, the furrows of the runner
slightly cross those of the bed stone, and thus a shearing, as well as a
grinding, action is obtained. It is partly for this reason that the master
furrows do not radiate from the center, but from points four or five degrees
wide of the center. This distance is called the draught; and the greater
the draught, the more quickly the material being ground travels from the
eye to the periphery.
A pair of French stones require dressing once a week, a flour mill week
being about 140 hours, generally. To keep the stones faces true a staff
is needed. This is built up of a number of strips of mahogany, glued and
bolted together to prevent warping. It is about 4 feet long by 5 inches
by 3 inches and one 3 inch face is kept dead true by testing it on, and
adjusting it to, an iron proof staff.
The true face of the wooden staff is lightly painted with a water paint.
It is then rubbed over the face of the stone, or rather, on the skirt, or
8 inch wide circle of the face nearest the periphery, when any unevenness
is at once marked by the paint, and must be dressed down as needed. If any
part of the stone between the eye and the skirt is marked, it must be dressed
off till the staff clears it.
Furrow strips are flat strips of wood, one the width of the furrows and
the other the width of the "lands" between. These are used as
rulers to mark the furrows, which are then dressed down to keep them to
the correct width and depth. On French stones, the wear is infinitesimal,
but the face soon wears too smooth to grind freely, and needs sharpening
every week by "cracking" the skirt, and dressing the smooth face
off the rest of the stone and the furrows, by lightly chipping with a sharp
mill bill. It is considered a good day's work (10 1/2 hours) for a stone
man to dress one wheat stone.
In the latter days of stone milling mechanical stone dressers were introduced,
diamonds being used to cut or dress the stones, instead of the steel mill
bill used by hand. They met with a certain amount of success, but the day
of the millstone had nearly passed by then, and they were too delicate for
the coarser dressing required for provender milling.
Within the last few years, composition millstones have superseded the old
fashioned, built up French stones. These are made from ground French burr,
mixed up with cement, in the same manner as concrete, and rammed into moulds
to form the millstones. Sometimes emery is used instead of French burr.
The advantages of the composition stone are: First, and most important,
that the face, formed of small pieces, does not glaze, and so always keeps
sharp; the only dressed necessary being a periodical deepening of the furrows.
Second, a more even grit is obtained.
High speed mills, fitted with small diameter stones, are largely used for
grinding various cereals, and especially for reducing the screenings, from
the wheat cleaning department of flour mills, to fine meal for mixing into
Maize. - Besides being ground on French burr, maize is often reduced
on other types of machines. A great deal of this grain is used in distilleries,
and is often ground on a three pair high roller mill. The rollers are fluted,
and the material having been broken down on the top pair, falls direct to
the second of further reduction, and then to the third pair for finishing.
Another type of machine is the high speed disc mill which grinds chiefly
by percussion: the fluted, chilled iron discs revolving in opposite direction,
and not actually coming in contact with each other, even when no grain is
passing through. Another type is the disintegrator (hammer mill), which
consists of beaters revolving inside a chamber at a very high speed, and
reducing the grain entirely by percussion. Maize is never required be ground
into a fine, soft meal as are most other cereals.
Barley. - Barley was generally ground on Derbyshire Peak stones, because
the coarseness and sharpness of the grit of these stones cut up the husk
better than any other. Since their introduction, composition stones have
been keen competitors of Peak stones.
Barley is required to be ground to a fine, soft meal, and the husks must
be well ground to obtain this. It is not unusual for millers to sift the
coarsest of the husks out of the meal and return them, continuously, to
the stone with the barley being ground, so that they may be reground two
or three times till enough to pass through the mesh of the sifter.
Peal barley is produced by scouring the husk off the berry and leaving the
endosperm unbroken. This is accomplished by means of a Peak stone revolving
on a spindle in a cage made of stout, closely woven wire, the grain being
scoured against the wire by the stone.
Oats. - Oats are ground for poultry feeding in much the same way
as barley. For making Scotch or Irish oat meal, the corn is first thoroughly
dried on a kiln. It is then run through a pair of Peak stones; the runner
being raised from the bed stone to a sufficient height to only scour the
oats and not grind them. By this means the hulls are rubbed off the oats,
and are then removed by winnowing. The groats are then ground into meal
of the required coarseness, either on millstones or on metal mill of various
types. The chief difficulty was to scour the oats sufficiently to remove
the hulls without damaging the grains that parted with their hulls first
and most easily. Machines have now been introduced to separate hulled and
unhulled oats, the latter being sent back for further scouring, while the
former are passed on to be reduced to meal.
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