THE BUILDER FEBRUARY 1927

The Precious Jewels

By BROS. A. L. KRESS AND R. J. MEEKREN
Continued. 

We now have to take up the second of the three jewels mentioned in
the two lists that we have been considering, namely that given us
by Prichard and that found in the anonymous Confession. It may be
well to quote them again for the sake of clarity, as the last two
installments of the series we were led into a discussion of
operative technical methods in order to obtain a fuller
understanding of the place of the first named jewel.

Prichard, then, said that the "movable" jewels were "The Trasel
Board, the Rough Ashlar an d the Broached Thurnel." The Confession
that the jewels of the lodge are the "Square Pavement, a dinted
Ashlar, and a Broached Dornal." It is the Ashlar that now falls for
discussion.

It will be recalled (1) that among what may be called the primary
versions of the old Catechisms that remain, the two just mentioned
are alone in offering any explanation of the purpose of the things
spoken of as jewels; and just as we came to the conclusion that the
Trasel Board and the Square Pavement were ultimately the same, so
in this case, too. Prichard calls the Ashlar "rough" while the
Confession says it was "dinted," but both alike say it was used for
making and testing the working tools of the Craft. The first saying
"it is for the Fellow Craft to try their jewels upon," evidently
referring to the "Square, Level and Plumb Rule" which had in an
immediately preceding clause been spoken of as the "Movable
Jewels," while the Scottish version says it is "to adjust the
square and make the gages by."

Now a rough ashlar--in the sense at least of a stone in its native
state as taken from the quarry--is an impossible standard for such
a purpose, so that we may confidently assume some error or
confusion in Prichard's account. What seems to be intended is some
kind of test block set up in the stone shed, or the "working lodge"
of the Mystery, by which the wooden instruments, all more or less
likely to get out of truth, might be tested and adjusted; or new
ones expeditiously made.

In the Study Club for January of last year (2) an operative
regulation was quoted from the Melrose MS. No. 19 of the Old
Charges, to the effect that no Master or Fellow was to let any
"Lose" or Cowan, "know ye privilege of ye compass, square, levell
and ye plum-rule." In the context it was clear that this meant the
methods of using these implements; the devices and short cuts of
what would now be called "shop practice." But the probability is
that not only did the "privilege" include the knowledge of their
use, and the right to use them without interference, but also, as
in the case of the "mouldsquares" that were discussed last month,
(3) of how to make them, or, at the least, of how to "adjust" them.

Thirty or forty years ago when machinists and fitters were still
accustomed to make their own tools instead of buying them, no
laborer was allowed to use or keep any, beyond perhaps a hammer and
a cold chisel or so. If he acquired them in any way they would
mysteriously disappear. No skilled man would ever dream of showing
him how to "true" a square, nor even allow him to watch the
process; and if he ever undertook to try to make one for himself,
as did occasionally happen, the news flew mysteriously through the
shop and there was a buzz like that of angry hornets in every
corner--and always, in some way or other, his enterprise was
brought to an untimely end.

THE FORTY-SEVENTH PROPOSITION OF EUCLID
Some Masonic writers have laid considerable stress upon the 3:4:5
triangle as a highly treasured operative secret and a few seem to
suppose that it would be used in making the squares. In certain
special circumstances this formula might be convenient in setting
out a right angle approximately on the ground, as for foundations,
though in most cases other methods would be better. The
qualification, approximately, is used advisedly, as apart from the
fact that the most refined and delicate measurements are correct
only within certain limits, there are in this particular method
multiplied chances of error. Three different measurements have to
be very accurately made, and then very accurately applied. On the
other hand there a number of ways of drawing one line perpendicular
to another which may be found in any elementary text-book of
Geometery and which all have the advantage that no measurements
have to be made at all as they depend entirely on drawing circles
of any convenient radius. It has only to be tried to become
perfectly obvious. And if practically a difficult and inconvenient
mode of drawing one line at right angles to another it is much more
a perfectly impracticable way of making one edge at right angles to
another, as any attempt to make a square will show.

This 3 :4 :5 triangle, too, has also been loosely spoken of as if
it were the same thing as the forty-seventh proposition of the
first Book of Euclid. It is of course only one very special case
covered by this famous proposition. It is hardly to be doubted
indeed that the properties of a triangle with sides that bore this
numerical ratio to each other were known ages before Pythagoras.
What he was so elated at discovering was not the particular and
special case, but the general truth that in any right-angled
triangle, no matter what were the lengths of the sides, the square
erected on the hypotenuse was equal in area to the combined area of
the squares on the other two sides.

THE STRAIGHT-EDGE

When it comes to making material objects with angles of a certain
size, geometrical methods are quite unsuitable, for they are
intended only for drawing lines on a plane surface. The normal
methods for obtaining a concrete angle, edge or surface, depend on
the use of some other object, already manufactured, as a gauge or
standard. Ultimately, and at the beginning, of course, some
standard has to be fashioned without this aid, and speaking
generally the various ways in which this may be done are
essentially the same as the methods of testing its accuracy when it
is made. Even the construction of geometrical figures depends on
the use of some object with a straight edge by which right lines
may be ruled.

The "straight-edge" indeed lies at the foundation, both of all the
constructive arts and of the exact sciences; and it will aid us to
realize its importance to craftsmen who had to make their own
measuring and testing appliances to understand the principle by
which it, or a plane surface, may be corrected to any required
degree of accuracy. If we take a piece of thin card and cut it
across with a pair of sharp scissors and then try the edge thus
produced against a ruler, we will find that it is really a complex
series of curves that we have produced; and if we go on trying to
cut a straight line "by eye" it will be found that though it may be
possible to come closer to the straight line represented by the
ruler, that very obvious variations from it still remain. We may
arrive at a closer approximation by noting the places where the
card touches the ruler and cutting them away with the scissors
until the limit of accuracy practicable by this rather crude method
is obtained.

But suppose we have no standard to begin with. Let us take the
piece of card and cut it as nearly straight as can be managed
without any guide, and lay it on a piece of paper and using it as
a ruler draw a line along the cut edge. Then if we turn the piece
of card over and apply the edge to this line the inequalities will
at once be apparent. By a process of cutting away the places where
the edge is too "high" it will be possible by continued trial to
rule a line with the card in one position and turn it over and draw
another and have the two lines coincide, if the pencil is not too
sharp. Though this line on close examination will be found thicker
in some places than others. If the card be replaced by some other
material, such as a thin piece of wood or a piece of sheet metal,
it is possible in this way, using appropriate means to "work the
edge," to produce a ruler of any desired degree of accuracy. 

It is not necessary to suppose that this was the actual method
employed, it is only an illustration of the principle underlying
the testing of a standard straight-edge. And where an edge or
surface can be tested it becomes possible to remove inequalities
and thus make a closer approach to the theoretical straight line or
plane. The essential thing in every possible method is the
comparison of one approximation with others, and the final result,
no matter how far and how carefully the process is carried, is
always a mean or average between the errors either in different
surfaces, or different parts of the same surface.

Now all the principal testing tools of the mason depend on the
"straight-edge" or "rule," which is in and by itself a very
fundamental one in this craft. The square consists of two straight
edges at right angles to each other, the level and plumbrule are
straight-edges in combination with a line and plummet hanging in
the one case at right angles and in the other parallel.

THE POINTS OF THE SQUARE

Two of the curious questions and answers relative to the square in
the confused account of Operative Masonry in Scotland given in the
Confession might be in part interpreted as embodying this idea.
They were quoted in the Study Club article for February of last
year. (4) The first passage seems to show a distinct appreciation
of the fact that the essentials of the level were to be found in
the square. It may be as well to reproduce the significant part of
the second one. We are told there are five points in the square,
which are as follows:

The square our master under God is one: the level's two: the
plumbrule's three: the hand rule's four: and the gage is five.

This might possibly be thus explained, the square used for its
normal purpose is the first point. If a plumbline be hung on top of
the "blade" of a square the stock can be set level by adjusting it
so the line will coincide with the edge of the instrument. In the
same way the blade can be used as a plumbrule. It can also
obviously be used as a straight-edge, if that be what is intended
by the term "hand rule." And finally, should we venture to suppose,
pace Mackey, that the edge of the square was sometimes graduated in
feet and inches, it would serve also as a gage or measuring
instrument. Of course the interpretation of such a cryptic
utterance as this apart from any living tradition will always be no
more than guesswork. It would be possible to interpret it quite
plausibly, by assuming the word square to be used in two senses --
i.e., the word "square" in the question, "How many points in the
square?" might refer to the "form" of the lodge; and in that case
the answer would simply enumerate the working tools present or
represented within it. The only reason for preferring the first,
and, it must be confessed, more complex explanation, is that it
fits in fairly well with the explanation that the author gives of
the previous question and answer, where it is said that the three
iron pins driven into the wall give both square and level.

A word may be said here regarding the accompanying cut in which are
collected typical forms of mason's working tools from different
sources and over a wide range of dates. We have already discussed
the rather dogmatic assertion made by Mackey in his Encyclopedia
about the true form of the mason's square. Not only will it be seen
that the square with limbs of unequal length is found represented
from Roman times to the end of the 16th century--it did not seem
worth while to look for later examples--but we must say also that
so far we have not come across a single case, earlier than the
purely emblematic jewels and designs of the eighteenth century in
which the limbs are equal, with one exception, the famous brass
square found in the foundations of Baal's Bridge, which, whatever
it was, was not an actual working tool.

Neither does there seem to be any reason in the nature of things
why a square with graduations marked upon it should be proper for
a carpenter but tabu to a mason. One swallow does not make a
summer, but in Fig. 11 there is represented an indisputable
example. It does not definitely appear however that Peter Ashton
was a Mason, though evidently a person of some local importance in
his day and place.

The curious square-headed form of compasses, of which two examples
are shown, appears sporadically in different places and periods.
The level from Strasburg is essentially of the same type as that
shown in the hands of Elias Dryham on a previous page.

ADJUSTING THE LEVEL AND PLUMBRULE

We have said that all these implements were made of wood. It is of
course possible that squares were occasionally made with a metal
blade, and that the level and plumbrule may sometimes have had
metal fittings, such as, possibly, a guard to keep the plumb bob
from swinging loose, or clamps to re-inforce the joints, but such
additions would make no essential difference to the character of
the appliances.

The plumbrule was simply a piece of wood, with a hole cut in one
end to give the "bob" room to swing freely while yet the line hung
close to the side of the wood. It is still used by bricklayers and
masons in Europe and is generally about four feet long and four
inches wide. The level took a greater variety of forms. One that
was very common was triangular; sometimes it was made like the
letter A. Sometimes again it was simply a short plumbrule mortised
into a straight edge like all inverted T. When it took this form it
was frequently braced on each side, thus combining both the T and
the triangle. Sometimes the braces were curved, thus forming the
prototype of many modern Senior Warden's Jewels. A very unusual and
highly ornamental form is shown in the illustration, already
referred to more than once, which was reproduced last month. (6) In
this the plumbline is suspended from a support in the form of a
miniature arch.

If in making a plumbrule a line be drawn along the board parallel
with the edge, and the cord suspended at a point on the line at the
top, it is obvious that when it coincides with the line previously
drawn that the edge of the instrument is perpendicular. But the
line may not be truly parallel. In order to test it, we set up a
stone, or a post by it, and when this is in position we turn the
rule upside down and suspend the cord as before. If it coincides
with the line again the instrument is accurate, and our post set
truly plumb. But if not the variation is double the error, and by
halving this distance a point is obtained that should be correct.
The post or stone can then be reset to the new standard and the
process repeated until as high a degree of accuracy has been
reached as we please, or as is practically possible.


The adjusting of the level is done on the same principle, only all
that is necessary is to turn the testing edge of the tool end for
end, the error then showing itself doubled as before. When the
plumbline marks the same point in either position the instrument is
"set." It is obvious that if there be a horizontal or perpendicular
surface at hand these tools could be very readily adjusted and
corrected. As they were always subject to many risks of injury
through rough usage we can see that it might have been very useful
to have a carefully squared stone accurately set level and plumb
for the purpose. In all machine shops standard surface plates and
straight-edges are kept by which those in every day use "at the
benches" may be periodically tested, and if necessary, "trued up."

MAKING A SQUARE

In these two implements, the plumbrule and level, we have obtained
our straight edge we have only to discover a certain point with
which the swinging plumbline must coincide to give the desired
result. With the square we have a more complex task. There are two
edges which must not only be quite straight, which in itself is not
so hard, but must also be at right angles to each other, which adds
very considerably to the difficulty. We say two edges: the modern
tool has four, both the inside and outside edges being "trued."
That of the medieval masons seems sometimes to have had only the
inside angle square, the outside being obviously quite different.
The square shown in the hand of William de Warmington is an
example. An even better one was shown last month. (5) Naturally it
adds to the difficulty of the task to get four straight edges into
this particular relationship, and for the mason's work we may judge
only the inside angle was required. A carpenter would find the
outside angle in many cases more useful than the inside, and it is
very likely that he made his own square to suit his special
requirements; for it is very possible that the mason's tools were
frequently made by the carpenters working on the same job--there
would always have to be carpenters to do the wood work, make
centers for the arches and so on. Still though they may often have
done this for their associate craftsmen, yet the masons would have
had to be able to do it for themselves, in their own fashion, if
the need arose. A carpenter would of course use his plane to get a
true edge, but the mason would naturally have no tools for working
wood. However, there are always more ways than one of doing a
thing. As an example a case may be cited of an elderly, highly
skilled machinist who made himself an inlaid bookcase in his spare
time. One day he showed it to a carpenter of his acquaintance, and
the latter greatly admired the very exact fitting of the many tiny
pieces of wood, but was highly amused when told how the work was
done. The machinist having no great skill with carpenter's tools
had used a file !

Now the mason who wanted to make a true straight edge out of a
piece of wood would have an obvious means of doing it, if there
were at hand a worked stone with a flat surface; he could rub the
edge down on the stone. If the piece of wood were fairly straight
to begin with and not too thick this would be a much more
expeditious method than might be supposed and would give very
satisfactory results.

The square would be made of a thin strip of wood, the blade,
mortised into a thicker piece, the stock. The latter would have its
edge made quite true before the blade was inserted. When this was
put in it could be tested in the same way as we did the piece of
card, only, as the angle has to be "right" as well as the edge, the
procedure will be to apply the stock to the edge of a flat surface
(such as that of the standard block we have supposed that the
ashlar might have been) and to draw a line. Then it would be turned
over and another line drawn from the same starting point. This
process gives not only the error in the edge, but the divergence
from a true right angle. By cutting, scraping or rubbing, the thin
edge of the blade can be gradually worked down so that a second
line drawn on reversal will coincide with the first. The edge of
the blade is then straight and the angle true.

NOTES

(1) THE BUILDER, October, 1926, pages 314-5.
(2) THE BUILDER, January, 1926, page 27.
(3) THE BUILDER, January, 1927, page 25.
(4) THE BUILDER, February, 1926, page 56.
(5) THE BUILDER, January, 1927, page 25.
(6) Ibid. January, page 25. It appeared as an illustration to the
article by Bro. N.W.J. Haydon on St. Alban's Abbey in the August
number, 1925, page 239. In addition to the level specially
mentioned in the test of the present article the exceptionally
large pair of compasses in the hands of the Master of the work is
to be noted; as also the peculiar form of the square. This seems to
be intentional and not merely carelessness on the part of the
artist, for in all the other technical details close observation is
evident. The outside angle of the square seems to be a right angle
however, only not parallel with the inside one. In the one shown in
the hands of the effigy of Master William of Warmington, of some
two centuries later, this is not the case, the outer angle being
distinctly obtuse. This is reproduced from the same article.

The illustration of the statue of Elias Dryham is from a photograph
very kindly sent to us by Bro. Ravenscroft.
