AN IMPROVED METHOD OF DRESSING MILLSTONES, AND APPARATUS IN CONNECTION THEREWITH
Year: 1871

page_text: PROVISIONAL SPECIFICATION left by Edward Copeland Stiles and
John Fenn Elsdon at the Office of the Commissioners of Patents,
with their Petition, on the 25th February 1871.
We, EDWARD COPELAND STILES, of No. 37, Alfred Place, Bedford
Square, in the County of Middlesex, and JOHN FENN ELSDON, of
Halstead, in the County of Essex, do hereby declare the nature of
the said Invention for "AN IMPROVED METHOD OF DRESSING MILLSTONES,
AND APPARATUS IN CONNECTION THEREWITH," to be as follows:-
:-
Our Invention consists in a particular kind of dressing for millstones,
and in an apparatus or rule for laying it off.
We give a similar dressing to both runner and bed stone, operating in
the following manner:-We first give a smooth and even face to the
stone; we then divide it into equal parts by lines drawn from the eye
to the circumference, the number of these lines varying according to the
size of stone used, for instance, a 4-foot stone would require 12 equal
divisions and so on in proportion to the diameter of the stone.
The rule we use for the purpose of laying off the dress is very simple
in its construction. Care must be taken that its inner or concave side.

page_text: has the same curvature as the circumference of the stone, and both sides
of the rule must be of the same radius. The length of the rule is equal
to the distance from the eye to the circumference of the stone, and it
must be made wider at one end than the other, the width being
regulated by the number of equal parts into which the stone is to be
divided. In using this rule we place the narrow end towards the cyc
of the stone, the broad end being towards the circumference; great care
must be exercised in the construction of this rule, the proper dressing
of the stone being dependent upon its accuracy. A section of the
bottom of the furrow through its whole length will be a curve, and its
radius equal to the circumference of the stone.
Our Invention will be best understood by reference to the accom-
panying Sheet of Drawing, and to the Figures and letters of reference
marked thereon, Fig. 1 being a top plan view of a stone, dressed
according to our Invention, and Fig. 2 a plan view of the rule which
we use in laying this dressing.
Having put a smooth face upon the stone by any suitable means we
place the point A of the rule on the point A at the eye of the stone and
the point B of the rule upon that B at the circumference of the stone.
We then mark off the size and shape of the rule on the stone; this is
called the large furrow and is made from an eighth to a quarter or even
three-quarters of an inch in depth, according to the article to be ground.
Barley requires a greater depth than wheat. There should be a slight
deepening in the dress from the eye to the circumference. The furrow
is cut nearly perpendicular on the inner sido and brought to a feather
edge on the outer side, so that the bottom has the same curvature as the
circumference of the stone. Furrows of the same description aro made
on the straight lines which divide the stone and are slightly cut out at
the eye, so as to receive the grain freely. After the large furrows are
laid off we lay the inner side of the rule on the outer line of the largo :
furrow and mark off its size. We then put the inner side of the rule
upon the last drawn line and mark off its size; the end of this towards the
eye will fall upon the larger furrow. On the size of the rule last marked
off we make a furrow the same shape as the larger furrow. We call
this the small furrow, and its end next the eye intersects one of the
larger furrows. These furrows, with the spaces intervening, fill up one
of the parts into which the stone has been divided. We then fill up
the remaining divisions in the same way. On the surfaces which are

page_text: now left we cut small grooves, say from six to ten, according to the
size of the rule. These grooves have the same curve as the rule and
are made of a slight depth regulated by the depth of the dress of the
stone. On the triangular surfaces we cut a groove along the line which
is next the larger furrow so that we preserve its edge. We also cut
another groove through the middle of the triangle from its acute angle
to the middle of its circumference, and we then cut grooves parallel
with it on each side until the angle is covered laying these grooves off
with the rule.
The accompanying Drawing represents the bottom stone. The upper
stone is laid off in a similar manner. When the upper stone is inverted
and placed on the lower one the curvature will be reversed, and when
in motion the inner curves of the top stone are in front.
It will be seen that one-half of each large furrow at the eye is behind
the diameter while the other half next the circumference is the reverse
of this. The small furrows have double the inclination of the large
furrows, their construction is such as to retain nearly all the grain to
the eye or centre of the stone until it is ground. Stones dressed on
other plans grind nearer to their circumference.
These grooves separate the bran from the flour more effectually than
in any other plan, and there is consequently a greater yield. Stones
dressed by this method cannot easily be choked and will not heat the
flour however long they may be run.