The
American Miller, and Millwright's Assistant
By William Carter Hughes
CONTENTS
Introduction
Explanation of Technical Words
PART FIRST.
On the First Principles of Mechanics
The Principle of the Lever
Inclined Plane
Pulley
Motion
Central Forces
Friction, or Resistance to Motion
Table of the Surface of Contact without Urgents
Table of the Results of Experiments on Friction, with Urgents, By M. Morin
Table of Diameter of First Movers
Table of Diameters and Circumferences of Circles, Areas and Side of Equal
Squares
Geometrical Definitions of the Circle and its parts
Centre of Percussion and Oscillation
Hydrostatics - Introduction
On the Upward and Downward Pressure of Water
Specific Gravity
Table of Specific Gravities
Hydrodynamic Power of Water Wheels
On the Action and Reaction of Water, as applied to Water Wheels
On the Construction of the Combination Reaction Water Wheel
Table of Velocities of Water Wheels per minute, with Heads of from 4 to 30
feet
Tasble of the number of Inches of Water necessary to drive one Run of Stone,
for Grist or Saw Mills on heads of 4 to 30 feet
Table showing the required length of Overshot and Breast Wheels, on heads of
10 to 30 feet
Howds's Direct Action Water Wheel
Directions for making the same
Jagger's Patent Turbine Water Wheel
Water Table for Jagger's Patent Turbine Water Wheel
Table showing the revolutions per minute of Jagger's Turbine
Table showing the Velocity of Water
PART SECOND
Remarks on the Culture
of Grain, & etc.
Table of Grain grown in the United States
On the quality of French Burr, as best adapted for Grinding Wheat and Corn
The Raccoon Burr Stone
Tram staffs
Directions for Preparing new Stones for Grinding
Directions for Laying out the Dress in Millstones
A special Treatise on the different Millstones Dresses now in use, with
practical remarks on their action
Directions for making Furrows on the most approved plan
Directions for Staffing and Cracking the face of the Millstone
On the best size of Millstones for different water powers
Practical remarks on Grinding Wheat and Corn
Remarks on Indian Corn, as an article of foregin consumption
On the Construction of Merchant Bolts on the old plan
Description of a new arrangement of the Merchant bolts on the most approved
plan
Directions for making bolting Cloths of all descriptions
Size of Mill Picks for Dressing Stones
Composition for Tempering Cast steel Mill Picks
On the use of the Proof Staff
On the amount of help necessary to be employed in a Mill of four run of
Stones, with their duties respectively
Hydraulics, as pertaining to the practical Millwright
Powers of gravity, Percussion, or Impulse with the reaction attachment
Remarks to the Millwright on the necessity of economy in planning and
arranging the Machinery of Flouring and Grist Mills
On Bedding the Stone
To find the velocity of the Stone per minute
Rule to find the Diameters of all Pitch Circles
To find how many revolutiond the Stone makes for one of the Water Wheel
On Machinery
Rule for constructing the Conveyor
On the construction of the Mill Dam
On the different kinds of Smut Machines now in use, with rules for making the
same
Remarks on the late invention for introducing air between Millstones when
Grinding
Description of the Author's Grain Dryer
Rules for the purchase of Wheat for Miller's use
The proper method for fitting the Bale and Driver to the Millstone
Remarks on Packing Flour
Table for Packing Flour
Remarks on branding Flour in Barrels
Muk's Patent bolt
On the Inspection of flour
Report on the Breadstuffs of the United States, their relative value, and the
injury which they sustain by transportation, warehousing, & etc., & etc.
Analysis of Wheat Flour
Result of the Analysis
Table for Reckoning the price of Wheat
Steam as applied to Propelling Mills
On the Construction of the Saw Mill
Table for Measuring Saw Logs
Harrison's Patent double Geared Mill
Utica French Burr Millstone Manufactory
Munson's Patent Machine for testing the balance of Millstones
Munson's Patent Eyes for Millstones
Bran Dusters and Separators Combined
Bonnell's Improved Process of Flouring
Analysis of Wheat Flour
Remarks on a New Description of Bolting Material for Grist Mills
Clasp Coupling Joint
Harris and Son's Smut Machine
Columbian Foundry and Burr Millstone Manufactory
Pilkington's Smut Machine
French Burr Millstone, Morris and Trimble
Booth's Grain Separator
Mitchell's Philadelphia French Burr Millstone
A History of the French Burr
Neyhart's Improved Grease Collar
Robert's Improved Shute for the Howd Water Wheel
Central Discharge Water Wheel
Wallace's French Burr Millstone
Burrow's Portable Grist and Flouring Mill
Johnson's Smut Machine
Ward's French Burr Millstone
Ward's Smut Machine
Dress for a Four foot Burr Millstone
Kinman's Self Discharging Flour Chest
Livingston's Burr Millstone
Fowler's Mill Furnishing Estabishment
Foster's, Stencil Engraver
Joval'sTurbine
Directions for obtaining Patents
INTRODUCTION
Having been requested by the publisher, Mr. Henry C. Baird, to enlarge
and
revise my book on Milling, I take pleasure in saying to my readers, that
my
first endeavors have been so well received by those engaged in the practical
operation of milling - for whose benefit the work was designed - that
this
edition will be found more to the purpose of both the miller and mill
owner. The
improvements made in milling during the last four years have been numerous
as
regards machinery. In merchant mills the greatest benefit has resulted
to our
business, within the last four years, in this particular; and the first
I shall
notice is, the present arrangement of merchant bolts, where the No. 10
cloth is
found to be more suitable throughout, both for return and dusters; as
it is
easily demonstrated, that where the flour is properly ground, if you
have length
of bolts sufficient for your grinding capacity, and all coarser as above
stated,
you will not require to regrind any portion of your offal a second time,
making
a great savings in the expense of manufacturing, and an improvement in
the
quality of the flour, as you bran will be much more inform than where
a second
grinding is resorted to. The next improvement of importance to millers
is that
of cleaning the grain perfectly. I have added to this edition a number
of very
excellent machines, (such as smut and winnowing machines,) all of which
are
necessary to give the flour a good color. The next machine I shall call
your
attention to, (that I consider no mill perfect without,) is Kinman's
Flour
Packer and Chest combined; an engraving of which is given. And last,
though not
least, indeed, is the improvement in the construction of wheat may be
considered
the key to the whole milling business, a good French burr millstone,
and those
made by Munson and Hart, of Utica, N. Y., in particular. This firm have
lately
added an improved eye to their millstones, that allows them to be run
at any
desired motion, without clogging.
The milling business occupies a respectable portion of our national
industry,
and gives employment to a large investment of capital in all the principle
wheat
growing States of this Union, which contributes largely to the benefit
of our
American farmers, in making a home market for Wheat and Indian Corn,
the two
principle staples of American produce.
The author of this work, having spent the best portion of his life in
the
pursuit of his calling as a practical Miller, begs to say, in preparing
this
work for the milling public, that his object is to establish a correct
guide to
a business which so little is known about, in a shape of substantial
reference,
instead of speculative theories, and that confined to the minds only
of those
who are attached to the business, either by employment of capital or
otherwise.
Special regard has also been paid to most of the essential improvements
which
have, of late, been introduced for the benefit of the miller. And we
can also
say, that we have omitted a large number of late inventions, from the
belief of
their utter worthlessness for a great many of the purposes for which
they were
designed; and those of our friends who furnished us with drafts and long
statements of their peculiar views on milling, will please accept our
thanks for
the same, and this, our apology for not giving them a place in these
pages.
With a full assurance and hope that this work may prove useful to all
engaged in
milling.
I respectfully subscribe myself,
Wm. C. Hughes.
Return to Table of Content
OVERSHOT OR BREAST SHOT WATER WHEELS
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The following table shows the required length of over shot or breast
wheels, on
falls from 10 to 30 feet, to drive from one to four run of four and a
half feet
stones, with all the necesary machinery for a merchant flouring mill.
The column
marked "Fall" shows the number of feet fall on the breast wheel,
or the diameter
of the over shot.
---------------------------------------------------------------------------------------------------------------------
Diameter
of overshot in fall - Number of run of stones.1 2 3 4
Multiply the number of run required by the length as stated in the table.
---------------------------------------------------------------------------------------------------------------------
First column-Diameter of water wheel
Second column-width of water wheel with one pair of millstones.
To determine the width of a water wheel to power; 2 pairs, 3 pairs or
4 pairs,
multiplty the length (width) of wheel in feet to determine how much wider
or
larger in diameter a wheel should be (diameter in the case of a breast
shot
water wheel).
length of wheel in feet x-twice-3 times-4 times.
---------------------------------------------------------------------------------------------------------------------
10' -7'
11' -6 1/4'
12' -5 3/4'
13' -5 1/2'
14' -5'
15' -4 1/2'
16' -4 1/4'
17' -4'
18' -4'
19' -3 3/4'
20' -3 1/2'
21' -3 1/4'
22' -3 1/4'
23' -3'
24' -3'
25' -2 3/4'
26' -2 2/3'
27' -2 1/2'
28' -2 1/2'
29' -2 1/2'
30' -2 1/4'
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Example
What should the length of either a breast or an overshot wheel be, in
drive 3
run of stones, on a fall of 18 feet? Look at 18 feet, the height of the
head;
then we have opposite 4 feet for 4 run, which, multiplied by 3, produces
12
feet, the length required.
ON THE QUALITY OF
FRENCH BURR, AS BEST
ADAPTED FOR GRINDING WHEAT AND CORN
There is no description of within, within our knowledge, that affords
so much
variety of texture, or that is so well adapted for grinding, as that
known as
the "French Burr." It varies from the closest of quality to
the openest and
poorest of the stone species.
We shall now, in this chapter give the necessary directions, which,
if attended
to strictly, will always insure the miller, who should always be the
person to
select the quality of millstone which will enable him to make the best
yields,
as well as a better quality of flour than he can otherwise do no any
other
description or selection of this kind of stone. In the first place, I
here
remark, that every well informed, practical miller, of at least ten years'
experience in the business, must be well versed in the difference of
the French
burr, which, long practice, his experience tells him that which is likely
to do
the best work, when set in order for grinding; he must be acquainted,
also with
what is termed the best stock for making millstones, as the stone is
imported
from France in blocks of various sizes, which blocks of stone differ
as much in
color as they do in quality. The first thing, to be done, on going to
the
millstone manufactory, is to select those sized stones you want. By examination,
you will soon be able to discover whether they suit these directions
or not; if
the stone is of a close appearance, and of a white color, without any
yellowish
spots in the seams, or where the blocks join each other closely fitted,
and the
said seems must be parallel with the diameter, as by being so they do
not break
off the edges of the seams, by interfering with the furrows; also, do
not forget
to take a mill pick, and go over every block, which you may do in a few
minutes,
and if they prove of an equal hardness, then we should recommend that
run as
being a good run of stones for grinding wheat expressly. If they should
prove,
after trying them in this manner, that some parts of the different blocks
of
which the stone is composed are rather softer, and incline to be open
about the
eye, do not take them, as it will take up more time in dressing them,
to keep
them in a good face, than two such as we have first described. The clear
white
and sometimes variegated stock, resembling marble, is the best description
of
French burr, for all uses; as that kind of stock is always free and hard,
and
holds an edge as long as any other color. For grinding corn expressly,
stone of
a different color may be used best for this kind of grinding; I say best
because
it is of a keener temper, and not so subject to soft, open places, as
the stone
first described. This kind of stock is of a pale, bluish cast, and more
particularly known to millers for its resistance of right good steel;
but after
being dressed, will grind more hard corn than any other kind of stone
in use. Of
course if this quality, we have dressed a large number of run for different
mills, expressly for flouring, which, with judicious management, answer
a very
good purpose; but I do not recommend this kind, as it requires a miller
of good
judgment to superintend in dressing them; for, in the first place, if
they are
allowed to get smooth, they are apt to heat, as well as grind wheat oily.
In the
next place, if they are dressed at all rough, they will make very specky
flour,
and grind harsh, - two evils not to be tolerated about a flouring mill,
further,
the nature of this kind of burr is of a dead, heavy texture, and entirely
unfit
for steam mills. Where the power is at all varying or unsteady, this
kind of
burr imparts to the flour a kind of grayish cast.
There is also another description of burr stock which I must here notice,
and
the worst of all others to the miller who has been so unfortunate as
to purchase
such stones with the least reasonable hope that he has got good ones.
This is a
burr of a yellowish color, called by some the Fox burr, and not at all
badly
named, as it is very deceptive in its appearance. In dressing this kind
of
stone, it resembles a knotty nature, with a good inclination to curl
as you
strike it with the pick. After you have ground with it for the space
of twenty
four hours, take it up, and it has all the appearance of being varnished
with
the best opal varnish, which makes the miller sigh for "the good
old days of
Adam and Eve, " when the gray Laurel Hill rock Stone were fashion,
or what the
Virginia miller calls "Virginia Creeper," either of which is
preferable to the
last described French Burr.
Having treated of the French Burr, we shall now direct out remarks to
that of
our American production, the Raccoon Burr.
ON THE RACCOON BURR STONE.
This description of stone is of American production, and its geological
nativity
is confined to the State of Ohio, not being known elsewhere. Its locality
is in
Muskingram and adjoining counties, known by the name of the "Flint
Ridge." This
stone is a description of burr, and makes a very good substitute for
the
imported or French burr. During may residence in, the State of Ohio,
I was
employed by the Messrs, Adams, of Muskingum county, who do a large business
in
flouring, being the most extensive millers in that part of the State.
One of
their mills, in which the author was employed, was of six run of stones,
all of
them of Raccoon burr, and having dressed them, the only conclusions I
drew, from
the work the stones made, was, that they required to be dressed oftner
than the
generality of the French burr. The reputation of this mill than stood
high in
New York for making a good article of superfine flour. The difference
in the
price between the Raccoon and imported being from 35 to 45 per cent cheaper.
They are put together in blocks and fitted up as the French burr, and
will
answer a good purpose for grist mills, or for grinding coarse grains,
such as
grist grinding generally consists of, for the use of the farmer.
DIRECTIONS FOR PREPARING
NEW STONES FOR GRINDING.
While the mill is in progress of building, the stones may be prepared
by the
miller who is to have charge of the running of the mill when completed,
as no
other than the head miller should direct the operation of putting in
the dress;
and any fault in their operation he should be held individually accountable
for.
It being necessary to take the stone out of wind before the dress is
laid out,
it may be done in the following manner: First, prepare yourself with
a good tram
staff of the following shape; have your staff dressed four inches wide,
with a
hole through it exactly four inches wide, with a hole through it exactly
in the
center; then frame two posts, two by three inches wide, at equal distances
from
your center hole, and then place a cap on the posts in which your elevation
screw is inserted, for the purpose of allowing the staff to come in contact
with
the stone. In addition to this, there is a plan different in its construction,
which is to use a bar of flat iron, of any suitable size, say half an
inch
thick, by one inch wide, or one and a half inch wide; bend it in a circular
form, and let it into the staff with screws; drill a hole through the
center,
exactly in range with the hole through the staff for the elevating screw.
This
description of staff is easier made than the first mentioned, and much
more
easily kept in repair. The spindle that the staff works on requires to
be an
inch in length; one of this size will work without springing. It will
be
necessary to have these screws, which are to be inserted into the staff,
in
three different sections of the hole which the spindle passes through.
The
object of these screws is simply to allow the staff to be trammed or
centered to
the face of the stone, by altering any three of those points which the
screws
represent. By placing your spindle properly in the eye of the stone,
the screws
may be dispensed with, and also a great deal of trouble in using the
screw to
train the staff, as every time the staff is taken off the spindle, in
replacing
it, the points require to be examined and trammed over. If the spindle
is
properly placed in the eye, no objection can be found in using the staff
without
screws, as the main center for taking the wind out of the stone is entirely
dependent on the spindle which the staff is suspended on; then the miller
must
center his spindle from the circumference of the stone, instead of centering
it
by the eye, as many do, supposing that the eye is always in the center
of the
stone, which is not always the case.
Being prepared now
to use paint for the staff, which may be prepared by mixing 2
ounces of either Spanish brown or Venetian red; the latter is preferable,
as it
shows on the stone better with spirits of turpentine or soft water. By
means of
the screw at the top of the spindle, you allow the staff to come down
so as to
slightly touch the stone, by which your work off all the high places,
until the
stone is perfectly out of wind, and may be known to be so when it paints
the
face all over exactly alike. For new stone, the eye blocks should be
worked
about a sixteenth below the rest of the face. The next part of the work,
being
to lay out and draft a proper dress, may be done as follows: Before we
dismiss
the subject of taking millstones out of wind, we will just refer to another
mode; namely, the using of three angles laid out on the surface of the
stone,
and each angle intersecting the other, which forms a center by working
the
lowest angle shown on the stone first to a good face, and working the
others
down to it. This is a mode we cannot recommend, as it consumes nearly
as long
again to prepare a stone with this plan as it does with the tram staff,
consequently is much more expensive, and its principles belong to a past
generation, but are mechanically correct, and answers in places where
a tram
staff cannot be got readily.
DIRECTIONS FOR LAYING
OUT THE DRESS IN MILLSTONES.
The first thing we shall notice under this head is the amount of draft
necessary
for your leading furrows. This must be varied according to the size and
quality
of your stone. Stones that are close require more than open ones, consequently
the miller's own experience must direct him to define the difference
between
close and open millstones, knowing that open stones have greater amount
of draft
than close ones. But I have found, from my own experience, that there
is, also
another essential point to be considered, that is, the particular dress
you use,
as in no quality of stone, either close or open, should as much draft
be given
to a stone of any size where a circle dress is used, as may be given
where the
dress is straight. My rule is, for a straight dress, in close stone,
an inch to
the foot of the diameter, and three quarters of an inch with the curve.
After
you have made up your mind on the amount of draft which you intend to
use, set a
piece of board in the eye of your stone, which for convenience we will
call a
draft board; then if you wish to use four inches draft, set your dividers
four
inches, and after you have found the exact center of your stone, place
the point
of your dividers in that center, and strike a circle on the board, called
the
draft circle. This is the first preparatory step of importance, the next
being
to know what way your stone is to run, whether with the sun or contrary;
if with
the sun, use circle dresses in preference to all others, will require
abundant
proof on this subject, we hope to give it to them; and if we succeed
in
enlightening them on the main error of all circular dresser, all we ask
of them
is to adopt what science and practical experience prove to be the better
mode.
To illustrate this subject fully, we take a millstone of four and a
half feet in
diameter, with a motion of 175 to 180 revolutions per minute, and prepare
it for
flouring with a circular dress, with furrows on a circle of once and
a half the
diameter of the stone. I pitch on this particular dress to illustrate
my views,
as eight tenths of all the circular dresses I have examined are drafted
at the
eye of the lowest number of inches generally given, being three and a
half
inches at the center, I ask, what will the angle be, that the furrows
will pass
each other, from the eye to the periphery? We suppose, that in such a
draft
above described, the angle of the furrows are equal; this should not
be the
case, when we consider that the center force increases as the distance
from the
center increases, caused by the circumference of every superficial inch
of the
stone increasing. We ask, then, how are you to bring the same amount
of meal on
this increasing velocity of the skirts of the stone, that you have at
the
center, when your draft, in both parts of your stone, are alike demonstrated
by
purely scientific principles, being governed by the laws of circular
motion, on
the same principles as above described? We affirm, that at least one
twentieth
of the pressure used on a stone of four and a half feet diameter, making
175
revolutions per minute, grinding 15 bushels per hour might be dispensed
with, or
avoided, if the draft or dress was applied in such a manner as to decrease
as
the central force increased, which would allow the angle of draft with
which
their furrows cross each other, in inverse proportion to their diameter.
If the
twentieth of the pressure need not be used; that is just one twentieth
of the
power saved, with at least an equal advantage gained of five per cent,
in the
quality of the flour; as the less pressure used in manufacturing, the
better the
flour after it is manufactured. This most all will admit.
With this dress, more time is consumed in keeping your stone in proper
order,
than should be, as all experienced millers will readily admit. The skirts
of the
stone with circular dresses are always lower than either the breast or
eye; and
the smaller the circle used, the greater this difficulty will exist,
it being
impossible to give the skirt as must of the meal, with this dress, as
its
relative proportions require. Where a stone four and a half feet in diameter
is
grinding, say 15 bushels per hour of wheat, and running night and day,
in twenty
four hours from the time it was started, the heat caused by the great
pressure
used becomes intense, as it forms a scalding temperature, which greatly
affects
the quality of the flour. To test this principle more full, I have compared
the
degrees of the temperature of the meal with this dress, and what is called
the
old fashioned straight quarter, as the meal issued from the stone, and
found the
following results:-
The circle dress ground the warmest by ten to twenty degrees of Fahrenheit;
both
the same kind and sized stone grinding about the same quantity. On two
separate
examinations of the heat of the meal, the stone with the circle dress
had 18
leading furrows, and the straight quarter 16 furrows.
Now, by this experiment alone, I do not say that this quarter, or straight
dress, is the one I should recommend all millers to use. No, by no means;
as the
disproportion in the draft of its short furrows condemns it alone. But
the
experiment went to prove its superiority over the circle, which was readily
discovered in the lively, rich color of the flour, and the clean appearance
of
the offal.
The different dresses, are all got up from those two, - the circle and
straight
quarter dress; and I must say, that their inventors were actuated more
by a love
of variety and novelty, than from the dictates of practical experience.
For that
reason, we shall not take time to notice them at further length than
considering
it no advantage to the miller, although there may be some who will value
it more
than any other dress (quarter dress) represented, because they have spent
more
time in getting up, than they have taken to examine the error they have
made by
introducing a combination of artificial drafts for millstones, contrary
to those
laws of circular motion and central forces which govern all kinds of
millstone
dresses, of whatever kind used.
We shall not present that dress for millstones that science and experience
show
to be best for all sizes of stone and varieties of central motion occasioned
by
the revolutions made per minute of the stone. These dresses represent
a
perfectly straight furrow, one inch and one eight in width, for a stone
four and
a half feet in diameter. The number of leading furrows should be from
16 to 20,
or 21, if the stone is more than ordinarily close; I prefer 21. Then
divide
those quarters with another furrow each, which will give 42 whole furrows,
allowing the short furrows to enter the leading ones in close stones:
This
dresses may be called, properly, the "new quarter dress;" its
superiority over
the old 16 dress is apparent to all, when we examine the drafts.
Millers who may think that there is too much face on the skirt, may
safely
increase the size of their furrows one eight of an inch on the skirt,
and in
very open stones may decrease it accordingly, as well as the number of
furrows.
I have the opinion of several of the best millers in the United States,
all
agreeing on this dress as being the best in use. By the use if it, we
entirely
dispense with that short furrow necessarily used in the old 16 quarter
dress, by
giving the short furrow in the new quarter dress about the same draft
as the
second furrow in the old, which serves to make the flour better, as less
pressure is used with the new quarter dress than with the old. The short
furrows
in the 16 quarter dress, that angle at which they cross each other being
too
obtuse to admit of cutting, as many, the angle being 84 degrees of draft,
they
push the meal out, and cannot act otherwise.
With the new quarter dress, as described, I should not recommend more
draft at
the eye of the stone than three and a half inches, where its motion is
from 160
to 180 revolutions per minute, for a stone of four and a half feet in
diameter,
with the same proportion, according to the size of the stone.
DIRECTIONS FOR MAKING
FURROWS ON THE MOST APPROVED PLAN
The manner in which furrows are shaped in very important, as, in discharging
the
meal, they will, if not properly made, make too many middlings, and allow
the
bran to pass out thicker than it ought to be.
the proper form, I have found, for them, is a perfectly true taper.
From the
first edge, commonly called the track edge, up to the second, called
the feather
edge, and of a depth of three eighths of an inch at the back or first
edge, up
to a sixteenth part of an inch at the feather edge of a new stone, and
not
deeper than the depth of a good heavy crack, when your stones are in
perfectly
good face for flouring.
Now, much pains in the mechanical construction of them may be saved
to the young
miller by the use of a gauge and staff. To dress his furrows you want
to make,
cut on wood, which will assist you. To make all your furrows precisely
the same
depth, the staff is a small, flat rule, four or five inches long, by
which you
can apply paint to your furrows to work then even, by which much time
is spared,
for the paint shows you all the high places, so that not one stroke of
the pick
need be lost.
For flouring, you furrows require to be as smooth as the face, as rough
furrows
make the flour specky. I have heard millers object frequently to their
bolts not
being right, when the whole cause lay in the rough manner in which their
stones
are dressed.
DIRECTIONS FOR STAFFING
AND CRACKING THE FACE OF THE MILLSTONE.
Every three months is as often as necessary to dress the furrows, but
in a mill
that does of good business, the face of the stones requires cracking
as often as
very four days, the stone running night and day.
Cracking the face, as it is termed, is an artificial mode of cutting
the face of
a millstone in parallel lines with the furrows by which the bran is cleaned;
consequently, when well done, a stone will grind a third faster than
without the
cracking face, and the flour is far superior. With stones cracked with
about
from 26 to 30 in every superficial inch of the face, reason tells us
that they
need not be pressed so close together. It requires a good deal of practice
to be
perfect in this part of the miller's art, but by the use of practice
we become
perfect in this, as well as any other branch of the business.
After the stones are taken up for the purpose of sharpening them, the
first
thing the miller should do is to take a soft sandstone, which should
be kept for
the purpose, and rub the face of the millstones all over with it. The
object of
this is to scour the face, which leaves it in better order to receive
the work
you are going to put to it. Sweep them off clean, and then apply your
staff. If
your stone should be higher about the eye and breast, skin off those
places, and
crack the balance; then your stone is ready for grinding. If you should
find
your stones in good face when you take them up, with the paint equally
distributed all over the face of the stone alike, being the highest about
the
eye, then the stones are considered to be in good face; then crack them
all over
nicely, without breaking the face, which must be done with a sharp pick;
then
apply a little tallow around your spindle neck, and if the spindle is
loose,
tighten it, and tram your spindle down, as they are in good order for
grinding.
SIZE OF MILL PICKS FOR DRESSING STONES
Much has been attempted to improve this important tool, but all I have
seen are
worthless, in comparison with that made from the cast steel bar, as generally
used. The size of the steel bar ought to be one and one eighth of an
inch
square; cut in six inches long, and draw it with a ture taper from the
center
each way. The best cast steel should be used for mill picks; and when
your picks
are done, they should be an inch and a guarter to three eighths wide.
At each
end of the steel should be hardened till they show a straw color for
two inches.
The blacksmith who sharpens them requires to pay a good deal of attention,
to
prevent the steel from getting too hot, as it is easily detected when
done; and
also to hammer them on an anvil that is smooth, to prevent the edges
from
cracking. I have taken a good deal of pains to get a recipe for making
a
composition for tempering cast steel, which may be found useful.
COMPOSITION FOR TEMPERING
CAST STEEL MILL PICKS
It is generally very difficult for the miller to get the blacksmith to
give the
steel its proper temper, from a want of a sufficient knowledge on the
part of
blacksmiths generally what the temper should be. We here insert a composition
for the purpose, which assists the process of tempering cast steel, by
assisting
the steel to retain its natural qualities and fineness of temper in opposition
to the great degree of heat used for drawing and tempering, as the oftener
steel
is heated, the more brittle become its fibres, which renders it worthless
to the
mechanic, and more particularly to the miller.
To 3 gallons of water add 3 ounces of spirits of nitre, 3 ounces of
spirits of
harthorn, 3 ounces of white vitriol, 3 ounces of salammoniac, 3 ounces
of alum,
6 ounces of salt, with a double handful of hoof parings; the steel to
be heated
a dark cherry red. Every miller should keep a large jug of this preparation
in
the mill, for tempering his picks; also, it must be kept corked tight
to prevent
evaporation.
ON THE USE OF THE PROOF STAFF.
The proof staff is made of cast iron, with a perfectly true face, and
set in a
case with a cover to it. It is for the purpose of keeping the wood staff,
that
is used to work the stone, by, in order; as, by applying one one the
other, you
will soon detect any error in your stone staff. A little sweet oil should
be
applied on the proof when about to try the order which your stone is
in. Rub the
face of the iron staff gently with a woolen cloth, with a small quantity
of oil;
then apply the wooden one; the oil of the iron staff will adhere to the
wood, so
as to guide to the highest spots. You can face your staff much better
with this
instrument than it is possible for a plane to do it, as, in finishing,
you use a
scraper of steel or glass. A proof staff is an article that should lie
in every
flouring mill; it is as necessary as a half bushel measure or toll dish.
In my
examinations of some of our best flouring mills, I have found this instrument
wanting, and was much surprised when many good practical miller have
told me
they never used one. the proof staff requires but to be seen and used
once, to
be the miller's favorite. They are made in all sizes, to suit all descriptions
of millstones, the general price being $25.
In those mills that have the proof staff in use, the offals are from
two pounds
to five pounds lighter per bushel than mills that have not.
A HISTORY OF THE FRENCH BURR
The following natural history of the most important of the stone species,
was
presented us by Mr. J. E. Mitchell, Millstone Manufacturer of Philadelphia.
It
contains valuable and interesting information for millers, and will be
read with
pleasing satisfaction by all our American millers;
For in "all the stone that this earth" is
best,
We millers think French Burr the best.
Four National Gold Metals have been awarded to Monsieur Roger fils,
for the
superior quality of his millstones and burr blocks.
MILLSTONES AND BURR
BLOCKS OF LA FERTE -SOUS- JOUARRE.
Establishment founded in 1802.
An extract from the Report of the National Academy of Paris on the Quarries
and
Millstone yards of M. Roger fils, at La Ferte Sous Jourarre:
The Committee of Arts and Manufacturers of the National Academy of Paris
appointed a special Committee to visit the produce of the Manufactory
of M.
Roger fils, Millstone maker, at La Ferte sous Jouarre.
The above Committee, consisting of men of special knowledge, and chosen
among
the members of the said Academy, hastened to fulfill their mandate, and
proceeded forthwith to La Ferte sous Jouarre.
The Committee give the following account of their proceedings:
"From time immemorial,
the millstone of La Ferte sous Jouarre has been
acknowledged as being infinitely superior to any other. Various quarries
exist
in France, Spain, Germany, and in almost all the other countries of Europe,
but
they are valueless when compared to the working under our present examination.
This fact is unquestionable, and is fully established by innumerable
experiments; it is of public notoriety that the grinding stones of La
Ferte sous
Jouarre perform much more work, yield meal much whiter and of much better
quality than any others, are enabled to grind to the greatest perfection
the
corn of every country, and moreover are made so as to last forty to fifty
years
at least.
"These immense
advantages insure them preferences wherever they are known,
although their price be higher than that of any others; but the results
obtained
by all intelligent miller do not make the pecuniary question a consideration,
for the grinding stones are the principle organs of the mill. We will
add that
the establishments in the environs of Paris are indebted for the very
great
repute in which their produce is held, to the exclusive use of the grinding
stones of La Ferte sous Jouarre.
"This little
town, situated in the valley of the Marne, (seine-et-Marne,) and
crossed by the latter as well as by the Paris and Strasburg railway,
which
greatly facilitate the egress of its produce, is surrounded by hills
in which
are embedded strata of a stone composed of pure silica earth, slightly
colored
by ferruginous deposits. This is the material which is now used in the
composition of good grinding stones, and which, at the same time as it
has
established the reputation of La Ferte sous Jouarre, has bestowed on
France a
branch of industry to which every other country is now, and ever will
remain,
trieutary.
"The range of
knolls which encircle the town is divided into three principle
hills:
"To the north,
on the left bank of the Marne, rises the Tarterel; to the south,
the eye rests on the picturesque hill of Jouarre, separated from the
valley of
the Manene by the minor Morin, into which it descends; to the west, on
the right
bank of the Marne, runs the eminence which contains the quarry of La
Justice.
"The Tarterel
itself, contains in general, within its strata, but a light salt
gray flint, with large openings, which is no longer in repute in consequence
of
the improvements made in the art of corn grinding.
"But at the
foot of the hill, beds of stone are to be found which are deservedly
much esteemed. The quarries which are situated on the same line, on this
side of
the Tarterel, produce a violet and pinkish flint, very appropriate to
every
system of grinding. The quarries of Bois-des-Cheneaux, in particular,
which line
the former, and of which the stone is light yellowish, sharp, not brittle,
and
very strong, is considered as producing first rate materials for grinding
stones.
"The hill of
Jouarre produces a great abundance of grinding stones of various
species. It contains good veins, but the strata are in general of little
consistence, the beds are not well connected, and the stone yielded,
which is a
blue slaty color, light blue and gray, is full of small porosities. The
quarries
of La Ferte sous Jouarre give large quantities of dark blue, light blue,
light
gray, yellowish gray, and sometimes white flint, with small openings.
"The quality
of this stone is in very high repute since the introduction of the
English system, of grinding.
"The valley
of the Marne, in the direction of Chateaux-Thierry, and nearly as
far as Eqernay, contains several beds of stone which are, at the present
moment,
is active working. The principle quarries are those of Villieurs-aux-Pierre,
Domptin, Charteves, Orbais, Margny, and Les Souvriens. The stone of those
quarries, which is mostly of the same quality and color as that of the
other
quarries of La Ferte sous Jouarre, is principally used in the manufacture
of
burr stones, and is, in consequence, in great demand for exportation.
"It would be
extremely difficult to state at what precise period La Ferte sous
Jouarre discovered the treasure which was ultimately to afford an easy
and
honest livelihood to its inhabitants. One fact is unquestionable, namely,
that
for several centuries past, excavations have been successively made with
the
most extraordinary good fortune, and that the results of such excavations
have
been exceedingly productive.
"But La Ferte
sous Jouarre does not enjoy exclusively the privilege of producing
stones for grinding purposes. Some ten or twelve years ago, chance discovered,
near the town of Epernon, a stratum of molar quartz, of which the flint,
sometimes gray, blue, or white, although does not afford the French millers
every quality that is to be found in the stone extracted at La Ferte
sous
Jouarre, must nevertheless be considered as a formidable rival for its
predecessor in the ultramarine countries where it arrives in burr stones;
and
the activity which is to be witnessed in the quarries of Saint-Lucien
and
Roches, shows, beyond doubt, that the trade of such stones has become
a very
important branch for foreign exportation. La Ferte sous Jouarre itself
affords a
striking proof of the fact, that the stone of Epernon has a very positive
merit,
since the manufacturers in the former town make use of it for their millstones.
"Now that you
are acquainted with the various beds of grinding stone, it is
important that you should have described to you, as succinctly as possible,
the
various systems of grinding which have been adopted, up to the present
day;
because those various systems require severally a special quality of
stone, and
because it is this requisite that has given to the various quarries the
repute
into which they have arisen.
"In former days,
large blocks of stone were extracted from the quarry. These
blocks were made into grinding stones of a single piece, or of two or
three
pieces, grossly put together, and the grinding stones were delivered
in this
state to the mills.
"Such grinding
stones had no furrows; but in order that the stones should have a
certain sharpness, that which had large cavities, or opening, was selected
in
preference to any other.
"These stones,
which were very large and had large openings were called French
stones.
"Some forty
years ago, the English discovered that by cutting in the grinding
stones a stated number of furrows, traced so as to facilitate the grinding
without thwarting the effect of centrifugal motion, a stone with small
openings
might be used to advantage, and the circumference of the grinding stone
might be
considerably decreased, without in any way diminishing the quantity or
perfection of the work. This system proved highly successful, and hence
the name
of English millstones, given to those of this description in France.
"The grinding
stone manufacturers of La Ferte sous Jouarre, who had at their
immediate convenience the best materials, who were acquainted with the
wants of
the French mill industry, (which has its superiority over that of all
Europe,)
and who were making wide strides toward improvement and perfection, were
very
soon able to make English grinding stones. They added to the latter system
a
third one, consisting of stone having rather large porosities, and which,
on the
account of the furrows, they called semi-English. But as they were award
that it
is important, in order that the grinding stone should be softer than
the other;
that all should have the same grain, the same porosity, the same color,
and that
consequently in stones made of a single block, chance alone could determine
the
good or bad quality, they forthwith manufactured grinding stones, made
up of a
great number of pieces, all exactly similar, taking care to suit their
choice to
the custom of the country in which the millstones are to work, to the
grinding
system, adopted by the miller, and lastly to the nature of the grain
to be
ground.
"Since then
this business has sprung into an art, the manufacture of millstones
requiring quite a special knowledge, and an ability not acquired by everybody.
"He begins by
the center piece or eye stone, which is most generally of a single
piece, and must be of great solidity, particularly for the runner, for
it is in
this eye stone that the iron cross, by which the stone is suspended,
must be
fixed. Round this center piece are set and fixed with plaster, the choice
pieces
previously bound together, and to which, as much as possible, the same
thickness
in the corresponding angles had been given. These pieces give the grinding
stone
the circumference it is desired to attain.
"At present
the joints of these several pieces are made with such nicety and
precision, that it is almost impossible to see the stone is not of a
single
piece.
"When the stone
has in this manner, reached the required size, it is banded over
to the smith, who encircles it by a large hot hoop, to hold the different
pieces
together; from the smith it passes into the dressing department, where,
by the
help of rulers perfectly straight, its surface is made even. The latter
operation being completed, it passes into the hand of the furrow cutter,
who
make and traces its divisions, and cuts in its surface a number of furrows,
according to the quality of the stone, or to the nature of the grinding
for
which it is intended.
"The next process
is to give sufficient aperture to the eye, and then the
stopping up process, which consists of filling up the upper face with
a sort of
masonry, composed of small pieces of millstones and plaster, and thus
giving the
necessary weigh and thickness. The bed stone does not require to be balanced;
this is not the case with the upper one or runner, which, having to revolve
on a
pivot, requires, as near as possible, its weight to be uniform in all
its parts.
"As, in spite
of all the care that is taken to balance the runner, it might
happen that this would not be acquired to perfection, room is left in
the
stopping up to place a few boxes parallel to each other. These boxes
are
intended for lead, when in the mill a perfect equilibrium of the grinding
stone
is requisite before the latter can be applied to their work.
Note: The fitst edition of The American Miller and Millwright's Assistant,
by
William Carter Hughes, was published in 1850, by Harsha and Hart, Detroit.
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