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    "_... And remembering these, trust Pindar for the truth of his
    saying, that to the cunning workman--(and let me solemnly enforce
    the words by adding, that to him only)--knowledge comes
    undeceitful._"

                                   --RUSKIN ("Aratra Pentelici").

    "_'Very cool of Tom,' as East thought but didn't say,'seeing as
    how he only came out of Egypt himself last night at bed-time.'_"

                                   --("Tom Brown's Schooldays").




    THE ARTISTIC CRAFTS SERIES
      OF TECHNICAL HANDBOOKS
      EDITED BY W. R. LETHABY

        STAINED GLASS WORK




[Illustration: CUTTING AND GLAZING

_Frontispiece_ (_See p. 137_)]




       STAINED GLASS WORK
    A TEXT-BOOK FOR STUDENTS
    AND WORKERS IN GLASS. BY
    C. W. WHALL. WITH DIAGRAMS
    BY TWO OF HIS APPRENTICES
    AND OTHER ILLUSTRATIONS

            NEW YORK
     D. APPLETON AND COMPANY
             MCMXIV




    Printed by BALLANTYNE, HANSON & CO.
    at the Ballantyne Press, Edinburgh




    _To his Pupils and Assistants, who, if they
    have learned as much from him as he has
    from them, have spent their time profitably;
    and who, if they have enjoyed learning as
    much as he has teaching, have spent it happily;
    this little book is Dedicated by their Affectionate
    Master and Servant,_

                                   _THE AUTHOR._




EDITOR'S PREFACE


In issuing these volumes of a series of Handbooks on the Artistic
Crafts, it will be well to state what are our general aims.

In the first place, we wish to provide trustworthy text-books of
workshop practice, from the points of view of experts who have
critically examined the methods current in the shops, and putting aside
vain survivals, are prepared to say what is good workmanship, and to set
up a standard of quality in the crafts which are more especially
associated with design. Secondly, in doing this, we hope to treat design
itself as an essential part of good workmanship. During the last century
most of the arts, save painting and sculpture of an academic kind, were
little considered, and there was a tendency to look on "design" as a
mere matter of _appearance_. Such "ornamentation" as there was was
usually obtained by following in a mechanical way a drawing provided by
an artist who often knew little of the technical processes involved in
production. With the critical attention given to the crafts by Ruskin
and Morris, it came to be seen that it was impossible to detach design
from craft in this way, and that, in the widest sense, true design is an
inseparable element of good quality, involving as it does the selection
of good and suitable material, contrivance for special purpose, expert
workmanship, proper finish, and so on, far more than mere ornament, and
indeed, that ornamentation itself was rather an exuberance of fine
workmanship than a matter of merely abstract lines. Workmanship when
separated by too wide a gulf from fresh thought--that is, from
design--inevitably decays, and, on the other hand, ornamentation,
divorced from workmanship, is necessarily unreal, and quickly falls into
affectation. Proper ornamentation may be defined as a language addressed
to the eye; it is pleasant thought expressed in the speech of the tool.

In the third place, we would have this series put artistic craftsmanship
before people as furnishing reasonable occupations for those who would
gain a livelihood. Although within the bounds of academic art, the
competition, of its kind, is so acute that only a very few per cent. can
fairly hope to succeed as painters and sculptors; yet, as artistic
craftsmen, there is every probability that nearly every one who would
pass through a sufficient period of apprenticeship to workmanship and
design would reach a measure of success.

In the blending of handwork and thought in such arts as we propose to
deal with, happy careers may be found as far removed from the dreary
routine of hack labour as from the terrible uncertainty of academic art.
It is desirable in every way that men of good education should be
brought back into the productive crafts: there are more than enough of
us "in the city," and it is probable that more consideration will be
given in this century than in the last to Design and Workmanship.

       *       *       *       *       *

Our last volume dealt with one of the branches of sculpture, the present
treats of one of the chief forms of painting. Glass-painting has been,
and is capable of again becoming, one of the most noble forms of Art.
Because of its subjection to strict conditions, and its special glory of
illuminated colour, it holds a supreme position in its association with
architecture, a position higher than any other art, except, perhaps,
mosaic and sculpture.

The conditions and aptitudes of the Art are most suggestively discussed
in the present volume by one who is not only an artist, but also a
master craftsman. The great question of colour has been here opened up
for the first time in our series, and it is well that it should be so,
in connection with this, the pre-eminent colour-art.

Windows of  glass were used by the Romans. The thick lattices
found in Arab art, in which brightly- morsels of glass are set,
and upon which the idea of the jewelled windows in the story of Aladdin
is doubtless based, are Eastern off-shoots from this root.

Painting in line and shade on glass was probably invented in the West
not later than the year 1100, and there are in France many examples, at
Chartres, Le Mans, and other places, which date back to the middle of
the twelfth century.

Theophilus, the twelfth-century writer on Art, tells us that the French
glass was the most famous. In England the first notice of stained glass
is in connection with Bishop Hugh's work at Durham, of which we are told
that around the altar he placed several glazed windows remarkable for
the beauty of the figures which they contained; this was about 1175.

In the Fabric Accounts of our national monuments many interesting facts
as to mediaeval stained glass are preserved. The accounts of the building
of St. Stephen's Chapel, in the middle of the fourteenth century, make
known to us the procedure of the mediaeval craftsmen. We find in these
first a workman preparing white boards, and then the master glazier
drawing the cartoons on the whitened boards, and many other details as
to customs, prices, and wages.

There is not much old glass to be studied in London, but in the museum
at South Kensington there are specimens of some of the principal
varieties. These are to be found in the Furniture corridor and the
corridor which leads from it. Close by a fine series of English coats of
arms of the fourteenth century, which are excellent examples of
Heraldry, is placed a fragment of a broad border probably of late
twelfth-century work. The thirteenth century is represented by a
remarkable collection, mostly from the Ste. Chapelle in Paris and
executed about 1248. The most striking of these remnants show a series
of Kings seated amidst bold scrolls of foliage, being parts of a Jesse
Tree, the narrower strips, in which are Prophets, were placed to the
right and left of the Kings, and all three made up the width of one
light in the original window. The deep brilliant colour, the small
pieces of glass used, and the rich backgrounds are all characteristic of
mid-thirteenth-century glazing. Of early fifteenth-century workmanship
are the large single figures standing under canopies, and these are good
examples of English glass of this time. They were removed from
Winchester College Chapel about 1825 by the process known as
restoration.

W. R. LETHABY.

_January 1905._




AUTHOR'S PREFACE


The author must be permitted to explain that he undertook his task with
some reluctance, and to say a word by way of explaining his position.

I have always held that no art can be taught by books, and that an
artist's best way of teaching is directly and personally to his own
pupils, and maintained these things stubbornly and for long to those who
wished this book written. But I have such respect for the good judgment
of those who have, during the last eight years, worked in the teaching
side of the art and craft movement, and, in furtherance of its objects,
have commenced this series of handbooks, and such a belief in the
movement, of which these persons and circumstances form a part, that I
felt bound to yield on the condition of saying just what I liked in my
own way, and addressing myself only to students, speaking as I would
speak to a class or at the bench, careless of the general reader.

You will find yourself, therefore, reader, addressed as "Dear Student."
(I know the term occurs further on.) But because this book is written
for students, it does not therefore mean that it must all be brought
within the comprehension of the youngest apprentice. For it is becoming
the fashion, in our days, for artists of merit--painters, perhaps, even
of distinction--to take up the practice of one or other of the crafts.
All would be well, for such new workers are needed, if it was indeed the
_practice_ of the craft that they set themselves to. But too often it is
what is called the _designing_ for it only in which they engage, and it
is the duty of every one speaking or writing about the matter to point
out how fatal is that error.

One must provide a word, then, for such as these also here if one can.

Indeed, to reckon up all the classes to whom such a book as this should
be addressed, we should have, I think, to name:--

(1) The worker in the ordinary "shop," who is learning there at present,
to our regret, only a portion of his craft, and who should be given an
insight into the whole, and into the fairyland of design.

(2) The magnificent and superior artist, mature in imagination and
composition, fully equipped as a painter of pictures, perhaps even of
academical distinction, who turns his attention to the craft, and
without any adequate practical training in it, which alone could teach
its right principles, makes, and in the nature of things is bound to
make, great mistakes--mistakes easily avoidable. No such thing can
possibly be right. Raphael himself designed for tapestry, and the
cartoons are priceless, but the tapestry a ghastly failure. It could not
have been otherwise under the conditions. Executant separated from
designer by all the leagues that lie between Arras and Rome.

(3) The patron, who should know something of the craft, that he may not,
mistrusting, as so often at present, his own taste, be compelled to
trust to some one else's Name, and of course looks out for a big one.

(4) The architect and church dignitary who, having such grave
responsibilities in their hands towards the buildings of which they are
the guardians, wish, naturally, to understand the details which form a
part of their charge. And lastly, a new and important class that has
lately sprung into existence, the well-equipped, picked
student--brilliant and be-medalled, able draughtsman, able painter;
young, thoughtful, ambitious, and educated, who, instead of drifting, as
till recently, into the overcrowded ranks of picture-making, has now the
opportunity of choosing other weapons in the armoury of the arts.

To all these classes apply those golden words from Ruskin's "Aratra
Pentelici" which are quoted on the fly-leaf of the present volume, while
the spirit in which I myself would write in amplifying them is implied
by my adopting the comment and warning expressed in the other sentence
there quoted. The face of the arts is in a state of change. The words
"craft" and "craftsmanship," unheard a decade or two ago, now fill the
air; we are none of us inheritors of any worthy tradition, and those who
have chanced to grope about for themselves, and seem to have found some
safe footing, have very little, it seems to me, to plume or pride
themselves upon, but only something to be thankful for in their good
luck. But "to have learnt faithfully" one of the "ingenuous arts" (or
crafts) _is_ good luck and _is_ firm footing; we may not doubt it who
feel it strong beneath our feet, and it must be proper to us to help
towards it the doubtless quite as worthy or worthier, but less
fortunate, who may yet be in some of the quicksands around.

It also happens that the art of stained glass, though reaching to very
high and great things, is in its methods and processes a simple, or at
least a very limited, one. There are but few things to do, while at the
same time the principles of it touch the whole field of art, and it is
impossible to treat of it without discussing these great matters and the
laws which guide decorative art generally. It happens conveniently,
therefore, as the technical part requires less space, that these things
should be treated of in this particular book, and it becomes the
author's delicate and difficult task to do so. He, therefore, wishes to
make clear at starting the spirit in which the task is undertaken.

It remains only to express his thanks to Mr. Drury and Mr. Noel Heaton
for help respectively, with the technical and scientific detail; to Mr.
St. John Hope for permission to use his reproductions from the Windsor
stall-plates, and to Mr. Selwyn Image for his great kindness in revising
the proofs.

C. W. WHALL.

_January 1905._




     CONTENTS

                                                                    PAGE

     EDITOR'S PREFACE                                                 xi

     AUTHOR'S PREFACE                                               xvii


     PART I

     CHAPTER I

     Introductory, and Concerning the Raw Material                    29


     CHAPTER II

     Cutting (elementary)--The Diamond--The Wheel--Sharpening--How
     to Cut--Amount of Force--The
     Beginner's Mistake--Tapping--Possible and
     Impossible Cuts--"Grozeing"--Defects of the
     Wheel--The Actual Nature of a "Cut" in
     Glass                                                            33


     CHAPTER III

     Painting (elementary)--Pigments--Mixing--How to
     Fill the Brush--Outline--Examples--Industry--The
     Needle and Stick--Completing the Outline                         56

     CHAPTER IV

     Matting--Badgering--How to preserve Correctness of
     Outline--Difficulty of Large Work--Ill-ground
     Pigment--The Muller--Overground Pigment--Taking
     out Lights--"Scrubs"--The Need of a
     Master                                                           72


     CHAPTER V

     Cutting (advanced)--The Ideal Cartoon--The Cut-line--Setting
     the Cartoon--Transferring the Cut-line
     to the Glass--Another Way--Some Principles
     of Taste--Countercharging                                        83


     CHAPTER VI

     Painting (advanced)--Waxing-up--Cleanliness--Further
     Methods of Painting--Stipple--Dry
     Stipple--Film--Effects of Distance--Danger of
     Over-Painting--Frying                                            94


     CHAPTER VII

     Firing--Three Kinds of Kiln--Advantages and Disadvantages--The
     Gas-Kiln--Quick Firing--Danger--Sufficient
     Firing--Soft Pigments--Difference in
     Glasses--"Stale" Work--The Scientific Facts--How
     to Judge of Firing--Drawing the Kiln                            105


     CHAPTER VIII

     The Second Painting--Disappointment with Fired
     Work--A False Remedy--A Useful Tool--The
     Needle--A Resource of Desperation--The Middle
     Course--Use of the Finger--The Second Painting--Procedure       118


     CHAPTER IX

     Of Staining and Aciding--Yellow Stain--Aciding--Caution
     required in Use--Remedy for Burning--Uses
     of Aciding--Other Resources of Stained
     Glass Work                                                      129


     CHAPTER X

     Leading-Up and Fixing--Setting out the Bench--Relation
     of Leading to mode of Fixing in the
     Stone--Process of Fixing--Leading-Up Resumed--Straightening
     the Lead--The "Lathykin"--The
     Cutting-Knife--The Nails--The Stopping-Knife--Knocking
     Up                                                              133


     CHAPTER XI

     Soldering--Handling the Leaded Panel--Cementing--Recipe
     for Cement--The Brush--Division of
     Long Lights into Sections--How Joined when
     Fixed--Banding--Fixing--Chipping out the Old
     Glazing--Inserting the New and Cementing                        144




     PART II

     CHAPTER XII

     Introductory--The Great Questions--Colour--Light--Architectural
     Fitness--Limitations--Thought--Imagination--Allegory            154


     CHAPTER XIII

     Of Economy--The Englishman's Wastefulness--Its
     Good Side--Its Excess--Difficulties--A Calculation--Remedies    156


     CHAPTER XIV

     Of Perfection--In Little Things--Cleanliness--Alertness--But
     not Hurry--Realising your Conditions--False
     Lead-Lines--Shutting out Light--Bars--Their
     Number--Their Importance--Precedence--Observing
     your Limitations--A Result of
     Complete Training--The Special Limitations of
     Stained Glass--Disguising the Lead-Line--No full
     Realism--No violent Action--Self-Effacement--No
     Craft-Jugglery--Architectural Fitness founded
     on Architectural Knowledge--Seeing Work _in
     Situ_--Sketching in Glass--The Artistic Use of
     the Lead--Stepping Back--Accepting Bars and
     Leads--Loving Care--White Spaces to be Interesting--Bringing
     out the "Quality" of the
     Glass--Spotting and Dappling--"Builders-Glazing"
     _versus_ Modern Restoring                                       163


     CHAPTER XV

     A Few Little Dodges--A Clumsy Tool--A Substitute--A
     Glass Rack--An Inconvenient Easel--A
     Convenient Easel--A Waxing-up Tool--An
     Easel with Movable Plates--Making the
     most of a Room--Handling Cartoons--Cleanliness--Dust--The
     Selvage Edge--Drying a
     "Badger"--A Comment                                             182


     CHAPTER XVI

     Of Colour                                                       198


     CHAPTER XVII

     Of Architectural Fitness                                        234

     CHAPTER XVIII

     Of Thought, Imagination, and Allegory                           248


     CHAPTER XIX

     Of General Conduct and Procedure--Amount of
     Legitimate Assistance--The Ordinary Practice--The
     Great Rule--The Second Great Rule--Four
     Things to Observe--Art _v._ Routine--The
     Truth of the Case--The Penalty of Virtue in
     the Matter--The Compensating Privilege--Practical
     Applications--An Economy of Time
     in the Studio--Industry--Work "To Order"--Clients
     and Patrons--And Requests Reasonable
     and Unreasonable--The Chief Difficulty the
     Chief Opportunity--But ascertain all Conditions
     before starting Work--Business Habits--Order--Accuracy--Setting
     out Cartoon Forms--An Artist
     must Dream--But Wake--Three Plain Rules                         264


     CHAPTER XX

     A String of Beads                                               290


     APPENDIX I

     Some Suggestions as to the Study of Old Glass                   308


     APPENDIX II

     On the Restoring of Ancient Windows                             315

     APPENDIX III

     PAGE

     Hints for the Curriculum of a Technical School for
     Stained Glass--Examples for Painting--Examples
     of Drapery--Drawing from Nature--Ornamental
     Design                                                          321


     NOTES ON THE COLLOTYPE PLATES                                   327

     THE COLLOTYPE PLATES                                            337

     GLOSSARY                                                        369

     INDEX                                                           373




PART I


CHAPTER I

INTRODUCTORY, AND CONCERNING THE RAW MATERIAL


You are to know that stained glass means pieces of  glasses put
together with strips of lead into the form of windows; not a picture
painted on glass with  paints.

You know that a beer bottle is blackish, a hock bottle orange-brown, a
soda-water bottle greenish-white--these are the colours of the whole
substance of which they are respectively made.

Break such a bottle, each little bit is still a bit of  glass.
So, also, blue is used for poison bottles, deep green and deep red for
certain wine glasses, and, indeed, almost all colours for one purpose or
another.

Now these are the same glass, and  in the same way as that used
for church windows.

Such  glasses are cut into the shapes of faces, or figures, or
robes, or canopies, or whatever you want and whatever the subject
demands; then features are painted on the faces, folds on the robes, and
so forth--not with colour, merely with brown shading; then, when this
shading has been burnt into the glass in a kiln, the pieces are put
together into a picture by means of grooved strips of lead, into which
they fit.

This book, it is hoped, will set forth plainly how these things are
done, for the benefit of those who do not know; and, for the benefit of
those who do know, it will examine and discuss the right principles on
which windows should be made, and the rules of good taste and of
imagination, which make such a difference between beautiful and vulgar
art; for you may know intimately all the processes I have spoken of, and
be skilful in them, and yet misapply them, so that your window had
better never have been made.

Skill is good if you use it wisely and for good end; but craft of hand
employed foolishly is no more use to you than swiftness of foot would be
upon the broad road leading downwards--the <DW36> is happier.

A clear and calculating brain may be used for statesmanship or science,
or merely for gambling. You, we will say, have a true eye and a cunning
hand; will you use them on the passing fashion of the hour--the morbid,
the trivial, the insincere--or in illustrating the eternal truths and
dignities, the heroisms and sanctities of life, and its innocencies and
gaieties?

This book, then, is divided into two parts, of which the intention of
one is to promote and produce skilfulness of hand, and of the other to
direct it to worthy ends.

The making of glass itself--of the raw material--the  glasses
used in stained-glass windows, cannot be treated of here. What are
called "Antiques" are chiefly used, and there are also special glasses
representing the ideals and experiments of enthusiasts--Prior's "Early
English" glass, and the somewhat similar "Norman" glass. These glasses,
however, are for craftsmen of experience to use: they require mature
skill and judgment in the using; to the beginner, "Antiques" are enough
for many a day to come.

_How to know the Right and Wrong Sides of a Piece of "Antique"
Glass._--Take up a sheet of one of these and look at it. You will notice
that the two sides look different; one side has certain little
depressions as if it had been pricked with a pin, sometimes also some
wavy streaks. Turn it round, and, looking at the other side, you still
see these things, but blurred, as if seen through water, while the
surface itself on this side looks smooth; what inequalities there are
being projections rather than depressions. Now the side you first looked
at is the side to cut on, and the side to paint on, and it is the side
placed inwards when the window is put up.

The reason is this. Glass is made into sheets by being blown into
bubbles, just as a child blows soap-bubbles. If you blow a soap-bubble
you will see streaks playing about in it, just like the wavy streaks you
notice in the glass.

The bubble is blown, opened at the ends, and manipulated with tools
while hot, until it is the shape of a drain-pipe; then cut down one side
and opened out upon a flattening-stone until the round pipe is a flat
sheet; and it is this stone which gives the glass the different texture,
the dimpled surface which you notice.

Some glasses are "flashed"; that is to say, a bubble is blown which is
mainly composed of white glass; but, before blowing, it is also dipped
into another  glass--red, perhaps, or blue--and the two are then
blown together, so that the red or blue glass spreads out into a thin
film closely united to, in fact fused on to, and completely one with,
the white glass which forms the base; most "Ruby" glasses are made in
this way.




CHAPTER II

     Cutting (elementary)--The Diamond--The Wheel--Sharpening--How to
     Cut--Amount of Force--- The Beginner's Mistake--Tapping--Possible
     and Impossible Cuts--"Grozeing"--Defects of the Wheel--The Actual
     Nature of a "Cut" in Glass.


No written directions can teach the use of the diamond; it is as
sensitive to the hand as the string of a violin, and a good workman
feels with a most delicate touch exactly where the cutting edge is, and
uses his tool accordingly. Every apprentice counts on spoiling a guinea
diamond in the learning, which will take him from one to two years.

Most cutters now use the wheel, of which illustrations are given (figs.
1 and 2).

[Illustration: FIGS. 1 AND 2.]

The wheels themselves are good things, and cut as well as the diamond,
in some respects almost better; but many of the handles are very
unsatisfactory. From some of them indeed one might suppose, if such a
thing were conceivable, that the maker knew nothing of the use of the
tool.

For it is held thus (fig. 5), the pressure of the _forefinger_ both
guiding the cut and supplying force for it: and they give you an _edge_
to press on (fig. 1) instead of a surface! In some other patterns,
indeed, they do give you the desired surface, but the tool is so thin
that there is nothing to grip. What ought to be done is to reproduce the
shape of the old wooden handle of the diamond proper (figs. 3 and 4).

[Illustration: FIGS. 3 AND 4.]

The foregoing passage must, however, be amplified and modified, but this
I will do further on, for you will understand the reasons better if I
insert it after what I had written further with regard to the cutting of
glass.

_How to Sharpen the Wheel Cutter._--The right way to do this is
difficult to describe in writing. You must, first of all, grind down the
"shoulders" of the tool, through which the pivot of the wheel goes, for
they are made so large that the wheel cannot reach the stone (fig. 6),
and must be reduced (fig. 7). Then, after first oiling the pivot so that
the wheel may run easily, you must hold the tool as shown in fig. 8, and
rub it swiftly up and down the stone. The angle at which the wheel
should rest on the stone is shown in fig. 9. You will see that the angle
at which the wheel meets the stone is a little _blunter_ than the angle
of the side of the wheel itself. You do not want to make the tool _too
sharp_, otherwise you will risk breaking down the edge, when the wheel
will cease to be truly circular, and when that occurs it is absolutely
useless. The same thing will happen if the wheel is _checked_ in its
revolution while sharpening, and therefore the pivot must be kept oiled
both for cutting and sharpening.

[Illustration: FIG. 5.]

[Illustration: FIGS. 6 and 7.]

It is a curious fact to notice that the tool, be it wheel or diamond,
that is _too sharp_ is not, in practice, found to make so good a cut as
one that is less sharp; it scratches the glass and throws up a line of
splinters.

_How to Cut Glass._--Hold the cutter as shown in the illustration (fig.
5), a little sloping towards you, but perfectly upright laterally; draw
it towards you, hard enough to make it just _bite_ the glass. If it
leaves a mark you can hardly see it is a good cut (fig. 10B), but if it
scratches a white line, throwing up glass-dust as it goes, either the
tool is faulty, or you are pressing too hard, or you are applying the
pressure to the wheel unevenly and at an angle to the direction of the
cut (fig. 10A). Not that you can make the wheel _move_ sideways in the
cut actually; it will keep itself straight as a ploughshare keeps in its
furrow, but it will press sideways, and so break down the edges of the
furrow, while if you exaggerate this enough it will actually leave the
furrow, and, ceasing to cut, will "skid" aside over the glass. As to
pressure, all cutters begin by pressing much too hard; the tool having
started biting, it should be kept only _just biting_ while drawn along.
The cut should be almost _noiseless_. You think you're not cutting
because you don't hear it grate, but hold the glass sideways to the
light and you will see the silver line quite continuous.

Having made your cut, take the glass up; hold it as in fig. 11, press
downward with the thumbs and upward with the fingers, and the glass will
come apart.

[Illustration: FIG. 8.]

[Illustration: FIG. 9.]

[Illustration: FIG. 10, A and B]

[Illustration: FIG. 11.]

But you want to cut shaped pieces as well as straight. You cannot break
these directly the cut is made, but, holding the glass as in fig. 12,
and pressing it firmly with the left thumb, jerk the tool up by little,
sharp jerks of the fingers _only_, so as to tap along the underside of
your cut. You will see a little silver line spring along the cut,
showing that the glass is dividing; and when that silver line has sprung
from end to end, a gentle pressure will bring the glass apart.

[Illustration: FIG. 12.]

This upward jerk must be sharp and swift, but must be calculated so as
only just to _reach_ the glass, being checked just at the right point,
as one hammers a _nail_ when one does not want to stir the work into
which the nail is driven. A _pushing_ stroke, a blow that would go much
further if the glass were not there, is no use; and for this reason
neither the elbow nor the hand must move; the knuckles are the hinge
upon which the stroke revolves.

[Illustration: FIG. 13.]

[Illustration: FIG. 14.]

But you can only cut certain shapes--for instance, you cannot cut a
wedge-shaped gap out of a piece of glass (fig. 13); however tenderly you
handle it, it will split at point A. The nearest you can go to it is a
curve; and the deeper the curve the more difficult it is to get the
piece out. In fig. 14 A is an average easy curve, B a difficult one, C
impossible, except by "groseing" or "grozeing" as cutters call it; that
is, after the cut is made, setting to work to patiently bite the piece
out with pliers (fig. 15).

[Illustration: FIG. 15.]

Now, further, you must understand that you must not cut round all the
sides of a shaped piece of glass at once; indeed, you must only cut one
side at a time, and draw your cut right up to the edge of the glass, and
break away the whole piece which _contains_ the side you are cutting
before you go on to another.

Thus, in fig. 16, suppose the shaded portion to be the shape that you
wish to cut out of the piece of glass, A, B, C, D. You must lay your
gauge _anglewise_ down upon the piece. Do not try to get the sides
parallel to the shapes of your gauge, for that makes it much more
difficult; angular pieces break off the easiest.

[Illustration: FIG. 16.]

Now, then, _cut the most difficult piece first_. That marked