REESE LIBRARY
()! THK
UNIVERSITY OF CALIFORNIA.
^eceii)ed
z/tccessious No.foSf/jy / . Chi ^ No.
EXERCISES
IN
WITH A SHORT TREATISE ON WOOD
WRITTEN FOR MANUAL TRAINING GLASSES
IN SCHOOLS AND COLLEGES
BY
IVIN SICKELS, M. S., M. D.
11 CF THE
-UNIVERSITY)
OF
NEW YORK : CINCINNATI : CHICAGO
AMERICAN BOOK COMPANY
COPYRIGHT, 1889,
BY D. APPLETON AND COMPANY.
prtnteb b^
B. Bppleton & Company
flew lorft, TH. S. B.
PEEFACE.
THE exercises in wood-working in this book were pre-
pared by me during the summer "of 1883, for the students
of the College of the City of New York. Subsequent
teaching suggested many changes and additions, until the
manuscript was scarcely preseSfeble. This manuscript has
been copied for other schools ; and now, in order that those
who have recently asked for it may receive it in better
shape, this little volume is printed.
I am indebted to Mr. Bashford Dean for the part relat-
ing to injurious insects, which was written expressly for
this book.
I. S.
NEW YORK, September, 1889.
TY
y
CTERSITT)
CN 8 " S
CONTENTS.
PAGE
INTRODUCTION .. . 7
PART FIRST. WOOD.
Structure of wood
Composition of wood
Branching of stems 19
Age of trees 20
Decay of trees 20
Season for cutting 21
Milling 21
Drying of wood . . . 22
Warping -23
Properties of wood . 24
Defects in wood 28
Measure and value of wood 29
Kinds of wood 30
Table of chief qualities of wood 38
Wood and iron 38
Wood-working trades 39
Parasitic plants 41
Timber-borers 45
Preservation of wood 52
PART SECOND. EXERCISES.
Tools (Plates A and B) 58
Drawing (Plate C) 63
Exercise 1. Use of the chisel 64
2. Use of the chisel (continued) 66
3. Use of the gouge 68
4. Use of the hammer .....> 70
6 CONTENTS.
PAGE
Exercise 5. Use of the jack-plane 72
6. Plane (continued) and marking-gauge 74
7. Use of the rip-saw 70
8. Use of the cross-cut .78
Sharpening tools with the oil-stone (Plate D) 80
Sharpening tools on the grindstone (Plate E) 82
Sharpening tools. Saw-filing (Plate F) .84
Exercise 9. Construction of a half-joint 86
10. Modified forms of the half-joint 88
11. Construction of a mortise- joint 00
12. Pinning the mortise-joint 92
13. Construction of a stub-mortise 94
14. Construction of a dovetail-joint 96
15. Construction of a miter-joint 98
16. Use of the miter-box . . . ' 100
17. Construction of a stretcher-joint 102
18. Uniting with dowels 104
19. Gluing 106
20. Examples of glued joints 108
21. Laying out a dovetailed box . . . . , . .110
22. Laying out and cutting the dovetails . . . . .112
23. Marking and cutting the tenons . . . . . . 114
24. Finishing the box v . 116
25. Hinging the top to the box 118
26. Construction of a drawer . . . . . . . 120
27. Construction of a blind-dovetailed box 122
28. Framing 124
29. Construction of window and door frames .... 126
30. Inclosing a building 128
31. Laying floors. Trimming . 130
32. Construction of a sash 132
33. Construction of a door . . . . . . . .134
34. Construction of stairs 136
35. Laying out and shaping the hand-rail . . . . . 138
36. Use of the frame-saw. Bending wood 140
37. Construction of a pattern 142
38. Shaping a boat-model 144
39. Veneering 146
Polishing . . . 148
Painting 149
Index . 151
EXERCISES IN WOOD-WORKING.
INTRODUCTION.
THE tendency of modern systems of education is toward
a proper distribution of practical with theoretical training.
The mind is to be aided in its development by the action of
the eye and hand ; and, in fact, all the special senses are
employed in objective teaching and manual exercises. In
school, the eye does more than interpret the printed page : it
recognizes the form and color of objects, it must calculate
their size, proportion, and distance, by observing and com-
paring them ; the hand is required to do more than writing :
it is taught to appreciate the weight, hardness, and other
properties of objects, by actual contact with them. At first
the introduction of drawing, modeling, and the use of tools,
into the courses of study was experimental; but, having
passed beyond that stage, these exercises are now known to
be efficient aids to a more natural and rapid as well as
stronger mental development.
There are some who, after being educated in the abstract
way, can apply their training successfully to practical pur-
suits, who see no necessity for manual or industrial training
in the schools, and who claim that superior and sufficient
development may be obtained by the study of mercantile
methods and the classics. These, however, form a very small
percentage of the people, and systems of education must be
arranged to stimulate all intellects, and not measured by the
accomplishments of a few. Our best educators recognize
this fact, and are modifying old systems by the greater intro-
duction of manual elements. No one doubts the value of
practical qualities, not only in ordinary people, but also in
8 EXERCISES IN WOOD-WORKING.
prominent leaders, who must be thoroughly practical a fact
so aptly illustrated by prosperous manufacturers and mer-
chants, successful engineers, great generals, and eminent
statesmen.
Manual training for the early cultivation of these prac-
tical qualities in students takes a place in the regular courses
of study : by means of it the reasoning power is more easily
awakened; knowledge of objects and the facts connected with
them are more readily understood and remembered; and,
above all, the accuracy and precision demanded by the prac-
tical studies, lead to closer observation and exactness in
others. This training begins in the lowest grades, and con-
tinues in its various applications through all the classes,
until in the higher grades we find sufficient physical strength
to handle the ordinary wood-working tools.
The prime object of all manual training, especially in
this country, is to aid mental development, and while this
fact must not be lost sight of, the training should be in some
useful art, or in some exercises which are introductory to
the useful arts.
Perhaps the most valuable of these studies is industrial
drawing, which is in itself a sort of universal language, a
medium between thought and execution. Its study cultivates
precision, and is well calculated to develop sound and accu-
rate ideas. Drawing naturally precedes construction, it pre-
pares the way for the work of the engineer, manufacturer,
or builder. Even the ideas of the inventor are jotted down
in a chance sketch, which is added to and modified at lei-
sure, leading to the finished sketch, from which the skilled
draughtsman produces the designs for the execution of the
work.
The studies of drawing and wood-working are closely
connected, and may be taught together with great advantage
to both. A simple object is roughly sketched on paper, its
measurements accurately made and marked on the sketch ;
from this a drawing is made with instruments, either full
size or to a scale, which is used in the workshop as a guide
to the construction of the object. Skill in sketching is a
INTRODUCTION. 9
valuable acquirement, and should be taught early in the
course of industrial drawing. These sketches should, if pos-
sible, be made from real objects, instead of charts, and should
always be accompanied by measurements. In sketching it
is well, first, to determine the number of diagrams necessary
to show the form or structure of the object, and allot for
each a certain space on the paper ; second, to place each
sketch in the middle of its space, of which it should occupy
about one half, thus leaving a margin for notes, measure-
ments, and small details ; third, to draw the relative propor-
tions of the object as accurately as possible ; fourth, to mark
on the sketch the measurements of each part.
Wood- working from the simple constructions of earliest
times has advanced with the necessities and customs of
nations, until at present it includes the complicated struct-
ures of modern requirements. Throughout all wood-working
trades we find certain general principles regarding the cut-
ting action of tools on wood, and the joining of different
pieces ; and, since those principles are more easily taught by
carpentry and joinery, these branches have been generally
adopted as educational aids.
The very extensive use of wood for building has given
rise in this country to a craft of carpenters whose improved
tools and methods of work are superior in many respects to
those of European workmen. Based upon these methods,
workshop practice in schools and colleges as applied to wood-
work does not stop with carpentry : its design is to prepare
the way for the entire field of mechanical arts ; so that car-
pentry and joinery are followed by turnery, carving, and
possibly a few lessons in pattern-making. These should be
followed by metal- work, such as forging, chipping, filing,
and, finally, with the elements of machine-work. The study
of mechanics as thus taught in the educational workshop
should be applied correctly, by methods which are the actual
but intelligent practice of the operating mechanic. As to
the time required, it can not be expected that the three to
five hours per week spent in the workshop are going to make
mechanics; far from it: several years of labor and experi-
10 EXERCISES IN WOOD-WORKING.
ence are necessary to produce -skilled workmen in any of the
arts.
This book deals with carpentry and joinery, and is divided
into two parts :
The First Part treats of the structure, properties, and
kinds of wood ; its manufactures and economic relations to
other substances, parasitic plants and insects ; and means of
preserving wood.
The Second Part contains the exercises, preceded by a
description of tools, and the manner of drawing used to illus-
trate the exercises.
These exercises are based upon American methods of
work and have been taught as follows : Each exercise was
explained, illustrated by sketches on the blackboard, and
then executed by the students. As the exercises advanced,
the blackboard sketches were prepared with more detail,
each being shown with its measurements designated. The
students copied these sketches and noted down such of the
verbal directions as they could. With the higher exercises
it was found necessary to issue duplicate copies, describing
and illustrating each step in construction, and also to exem-
plify by models made by the instructor.
Exercises 1 to 8 introduce the chief wood-working tools
and methods of marking. These exercises should be executed
with much care and patience, and if necessary repeated, to
insure better results in subsequent work.
Following exercise 8 are directions for sharpening tools.
But students should not attempt to sharpen tools until they
have had considerable practice in the use of them ; especially
saw-filing, which requires remarkably good judgment, keen
eye-sight, and a steady hand.
Exercises 9 to 20 give instructions for marking out and
shaping simple joints.
Exercises 21 to 27 instruct in the methods employed in
uniting several pieces to make a complete structure.
Exercises 28 to 35 give the details of ordinary house-car-
pentry, from which the student may obtain particulars for
the construction of models, and the apprentice the actual
INTRODUCTION. 11
building of the various parts making up a wooden dwell-
ing.
Exercise 36 shows the use of the frame-saw, and methods
of bending wood.
Exercise 37 gives an example of pattern- work, and illus-
trates the manner of uniting pieces for economy of labor.
Exercise 38 instructs in shaping by the use of templets.
Exercise 39 treats of veneering, followed by directions for
painting and polishing.
s*Tf&&^* LIBfi/f^yN^
f OF THE \
(UNIVERSITY)
V. f *S
PART FIRST.
STRUCTURE OF WOOD.
IF we examine the stem of a young plant, we find three
distinct tissues composing it : On the outside is the bark or
protecting tissue ( a, Fig/ 3) ; inside there is a soft material,
made up of many-sided, thin- walled cells, which constitute
the living portion (6, Fig. 3) ; and arranged in a circle in this
soft tissue are several fibrous bundles (c, Fig. 3), giving to the
stem its strength to support the branches and leaves. Be-
cause of differences in the character of these bundles, we
separate stems into three classes; and the pine, palm, and
oak may be taken as types of each.
In the pine and oak the bundles are similarly arranged,
and consist of an outer portion called bast (d, Fig. 3), and an
inner portion called wood (e, Fig. 3) ; between these is a thin
layer of active cells, which multiply by division to form the
bast and wood ; this layer is called cambium (/, Fig. 3), and
adds each year to the size of the bundle. In the palm the
bundles arise from active cells at the growing point of the
stem, and continue down the stem, sometimes becoming
smaller, but retaining a rounded form.
As the stems grow older and larger, we find, in the pine,
that new and branching bundles appear between the first
ones, forming, during the season, a circle of bundles, which
constitutes the first annual ring. This ring is interrupted by
plates of tissue communicating between the pith, on the in-
side of the ring, and the soft tissue on the outside. In a cross-
H EXERCISES IN WOOD-WORKING.
section of the stem these plates are seen as lines, called medul-
lary rays, radiating from the center toward the bark. At the
FIG. 1. Diagram of a stem with a cambium layer. A, section cut across the bundles ; B,
section in the direction of the bundles ; 1, 2, 3, first, second, and third annual rings ;
a, a, pith ; 6, 6, pitted vessels ; c, c, wood-cells ; d, spiral vessels, found only in the first
annual ring ; e, cambium-cells ; /, gf, 7i, layers of bark ; L i, medullary ray. (After
Carpenter.)
end of the season growth stops, to be resumed again in the
spring. The slow and condensed growth of summer, and the
rapid, open growth of spring, give rise to a peculiar mark in
the bundles which indicates each year's increase, so that by
counting these marks or the annual rings we may ascertain
the age of a tree.
The last few rings formed are engaged in transporting or
storing up nourishment, and give rise to what is called the
sap-wood. The rings inside of the sap-wood serve only for
support, and make up the heart- wood of the tree.
In the palm, new bundles arise, placed irregularly in the
soft tissue or pith, and by tracing these bundles throughout
the plant we see that they extend, usually without branch-
ing, from the apex of the leaf to the small ends of the roots,
so that for each new leaf there will be in the stem new bun-
dles.
STRUCTURE OF WOOD.
15
FIG. 2. Diagram of a palm-stem. A, cross-section ; B, longitudinal section ; o, a, soft
tissue ; b, 6, vessels or tubes with pitted sides : c, c, wood-cells or fibers ; d, d, vessels
with spiral markings. (After Carpenter. >
In the oak we have the same appearance regarding the
annual rings and medullary rays as in the pine :
Epidermis a., bark.
f pith...gr.
Active cells. . . 6 -j medullary ray . . h.
(. f cambium . ./.
""BBS?:..! US'
bast-cells., d.
FIG. 3. Section of stem.
Examining more closely these wood-forming bundles, we
find them composed of cells with a variety of forms and walls
of varying thickness and peculiar markings. In the pine
group the cells are long, with pointed ends, and walls marked
by characteristic elevations called bordered pits (Fig. 4). These
16
EXERCISES IN WOOD-WORKING.
pits arise during the thickening of the cell-wall, which can
not take place on the thin circular membranes (Fig. 10, c),
through which the sap passes, but forms arches with open
tops over them, and thus gives the bordered appearance. In
FIG. 4.
FIG. 5.
FIG. 6.
FIG. 4. Section of pine-wood cut parallel with the medullary plates, a, spring growth,
with large bordered pits : 6, summer growth, with smaller bordered pits ; c, medul-
lary tissue.
FIG. 5. Section at right angles with the medullary plates, cf, bordered pits ; e, medullary
tissue.
FIG. (5. Cross-section of the same. /, summer growth ; g, spring growth ; 7i, medullary
ray.
the heart-wood these thin membranes have broken down,
allowing a free passage of air or water through the cells.
In spaces between the wood-cells there are, in most of the
pines, canals containing resin dissolved in turpentine. The
thin plates of tissue forming the medullary rays are com-
posed of small cells, with thin walls in the outer annual
rings, but in the heart-wood with walls very much thick-
ened.
The isolated bundles of the palm are composed of various
elemeiits,some of which simply support, as the bast and wood
fibers ; others support and conduct, as the vessels and wood-
cells ; these latter convey air, and water charged with min-
eral matters absorbed by the roots.
The bast-fibers are on the outside, surrounding the bundle,
and are very long, narrow, many-sided cells, with pointed ends,
the walls very much thickened and marked with oblique pores.
The wood-fibers are on the inside of the bundle, similar to
the bast-cells in every respect, except that they are shorter,
and occasionally used for conducting and storing up nourish-
STRUCTURE OF WOOD.
ment. The vessels or tubes are large and few, and present
varied markings ; the larger are pitted, the smaller either
S
FIG. 7. Palm-bundle, a, a, bast ; b, pitted
vessel ; c, wood-cells ; d, smaller ves-
sels ; e, soft tissue.
ringed, spiral, netted, or ladder-form. The wood-cells are-
like those of the pine group, but with simple in place of bor-
dered pits. There are present, also, sieve-tubes with clusters,
of small perforations in sides and ends, and a group of long,.
thin-walled cells similar to the cambium-cells of the. pine
and oak. Frequently in the vicinity of the
vessels are found thin- walled cells with blunt
ends, separated from the vessels and sur-
rounding cells by membranous pores ; these
cells, which are somewhat similar to cambi-
um-cells, serve the purpose of conducting
and storing up the organic materials formed
in the leaves.
In the oak group the wood is composed
of compact bundles made up of the same
fibers, cells, and vessels found in the palm,
with the exception of the bast-fibers, which are formed out-
side of the cambium zone and constitute the inner bark. .In?
the spring growth the vessels are large and numerous ; int
the autumn they are much smaller, and in some cases may
be absent. By this variation in the size and position of the
bundles the annual rings become distinctly marked. The
medullary rays in the heart- wood vary in thickness, and in
many of the woods the cells composing them become solid.
2
9 _p itted ves s e is
18
EXERCISES IN WOOD-WORKING.
COMPOSITION OF WOOD.
Newly formed cells have the wall composed of cellulose, a
substance similar to starch in composition. The contents of
the cell are made up of a number of substances, the chief of
which are albuminoids, starchy matters, oils, and water with
dissolved sugars, gums, and acids.
In the heart-wood the contents have
disappeared, air taking their place, and
the cell- wall has become very much thick-
ened by a deposit within the cellulose of
a dense substance called lignin, which
gives to wood its elasticity and hard-
ness.
In the living tree, air and water are
present in varying quantities, depending
on the season and kind of wood. The
amount of water is frequently as much
as fifty per cent. During the seasoning
of pine, about twenty per cent of water is
removed from the wood. This may be
called free water, because it exists in the
plant with all the ordinary properties of
water. But there is also in pine-wood
about the same amount of water, which is
chemically combined with carbon to form
cellulose and lignin. The presence of this
modified water may be demonstrated by
placing the wood in a partially closed iron
vessel, and heating it red hot ; the wood
is reduced to charcoal, while water is given
off, together with a small quantity of gases, oils, and other
matters.
The elementary composition of wood varies according to
the kind, the soluble matters in the soil, and the amount of
moisture absorbed by the tree. Generally wood contains
large quantities in proportion of carbon, hydrogen, and oxy-
gen ; less of nitrogen, sulphur, and potassium ; and small
FIG. 10. Diagram show-
ing growth of the
cell-wall.
1. Cambium-cell : a, pro-
toplasm or living con-
tents of the cell ; 6,
nucleus in the proto-
plasm ; c, thin mem-,
brane through which
the sap passes. In the
heart- wood this mem-
brane has broken
down, as at d.
2. Protoplasm forming a
wall of cellulose.
3. Protoplasm has disap-
peared. Cellulose
changing into lignin.
4. Cell-wall composed of
lignin and thin mem-
brane.
BRANCHING OF STEMS.
19
quantities of iron, phosphorus, calcium, sodium, and silicon,
with traces of many other elements.
If wood is burned in the open air, the carbon, hydrogen,
nitrogen, sulphur, and part of the oxygen are driven off in
gaseous form ; the other elements remain, and constitute the
ash, of which the principal ingredient is potassium.
The amount of ash is greater in the palms and least in
the pines. The percentage of a few are as follows :
Oregon pine 0'08
Red cedar 013
Redwood 014
Chestnut 018
White pine 019
Whitewood.. . 0'23
White oak 0*41
Hickory 073
Black walnut 079
Palmetto 7'66
Black iron- wood 8 '31
Spanish-bayonet _8'94
BRANCHING OF STEMS.
In the middle of a forest, trees grow straight, tall, and
slender, as in Fig. 12, because it is necessary for them to
Fio. 11.
FIG. 12.
FIG. 13.
FIG. 11. Shape of a tree on the border of a forest, a, broken branch exposing surfaces
for boring insects or fungus spores.
FIG. 12. Young forest tree. b. b, branches die for want of sunlight.
FIG. 13. Shape of forest tree with straight stem and crown of small branches and leaves.
push up the tops in order that they may receive sufficient
sunlight, to enable the leaves to digest the plant-food and
20 EXERCISES JN WOOD-WORKING.
increase the diameter and height of the stem. Lower branch-
es last only a few years, then die, and are broken off (6, Fig.
12). On the margins of the forest and in open places, trees
send out numerous branches, and stems become large in di-
ameter, but remain short (Fig. 11). The bordering trees,
while they serve as a protection from the wind for those in-
side, furnish knotty and cross-grained lumber ; those inside
produce the straight-grained and valuable wood (Fig. 13).
Members of the palm group rarely have branching stems.
In growth, the stems remain long and slender, but frequently
larger at the top than at the base.
AGE OF TREES.
Like animals, in growth and development plants are sub-
ject to influences of climate and nourishment. In its proper
latitude, and with an abundance of water and food in the
soil, a tree adds to its annual growth and lives to a great age.
But when the soil becomes exhausted of the necessary ele-
ments, or a more robust species crowds roots and leaves, then
a tree begins to show signs of decay. It is difficult to estab-
lish rules regarding the proper age for cutting. For timber,
most trees are considered fit at about one hundred years, al-
though oak may furnish excellent timber at two hundred
years. The purpose for which the wood is to be cut deter-
mines the proper age. Young trees show a closer grain and
give a more elastic wood than old ones. Very old trees, al-
though apparently sound, are found to be partially decayed
in the middle of the trunk, so that the elasticity and hard-
ness of the wood are replaced by a characteristic brittleness.
DECAY OF TREES.
As long as a tree is in a healthy condition, its top or
crown retains its small branches, but when these refuse to
send forth leaves, and break off, it is a sign of decay, and the
tree should be cut down and put to some use ; for, if allowed
to stand, its decay, aided by parasitic insects, will proceed
rapidly until there remains nothing but a shell, composed of
the growing zone and a few of the last annual rings, and its
SEASON FOR CUTTING. 21
value for any purpose will become very much lessened or
entirely lost.
Breaking or sawing off a branch and leaving the wound
exposed will furnish an opportunity for fungus spores *or
boring insects to begin the destruction of the wood.
Cutting down trees on the border of a forest, or clearing
a large space within it, is destructive to the tall trees remain-
ing exposed to the winds and elements. The swaying of the
stems in a storm causes the tender root-hairs to be broken
off, thus preventing absorption of sufficient nourishment by
the root, and shortening the life of the tree.
SEASON FOR CUTTING.
The proper time of the year for cutting down trees is an
important matter. In the spring and late summer the outer
portion of the wood is charged with elements which tend to
hasten its decay. In the drier summer months and in winter
the growing and conducting cells are less active or altogeth-
er dormant, and better wood may be secured if cut during
those times of the year. Oak is said to be more durable if
cut just after the leaves have fallen.
The trees are cut with axe or saw, and skill is required to
fell a tree so that it will come safely to the ground, and not
hang suspended to neighboring branches or crush young
trees in its fall. An experienced woodman will direct the
falling tree exactly where he wishes. He cuts on the side
and about at a right angle to the direction in which he wish-
es the tree to fall ; next he cuts on the opposite side, and, if
necessary, a few inches higher.
The tree, after falling, is cleared of its branches and sawed
into lengths, according to the future use of the wood.
MILLING.
If near a stream, the logs are rolled or drawn to the water
and floated to the mill, where they are examined and grouped
according to fitness for special uses. A long immersion of
the logs in water removes soluble substances in the sap-
wood, but is said to injure the heart-wood by rendering it
22 EXERCISES IN WO OJ)- WORKING.
less elastic. Water, however, is the easiest and cheapest
means of transporting logs. In the absence of an available
stream, the logs are carried on wagons or sleds to a railway
or directly to the mill.
The old-time mill, with its single upright saw and ancient
water-wheel, is seldom seen nowadays ; it has given way to
gang and circular saws, and even to giant band-saws, run by
turbine or steam. Frequently portable engines and saws are
employed on the ground where the trees are cut, thus saving
the transportation of the waste portions of the logs.
Logs are sawed into either timber, planks, or boards, and
these constitute lumber. Timber includes all of the largest
sizes, such as beams and joists. Planks are wide, of varying
lengths, and over one inch in thickness. Boards are one inch
or less in thickness, and of varying lengths and widths.
Lumber may be resawed into the many smaller sizes which
are to be found in the seasoning and storing yards.
The rough-sawed lumber may be planed at a mill, and is
then called dressed lumber, of which there is a great variety,
adapted to almost every purpose for which wood is used.
Dressed planks and boards when free of all defects are called
clear, and their regular sizes are f, i, 1-J, If, and If inches,
which are one eighth of an inch less in thickness than sawed
lumber. One-half-inch dressed is made by resawing one-aiid-
a-quarter-inch lumber.
DRYING OF WOOD.
In the preparation of lumber for use, it is necessary to
remove its moisture, after which the wood is seasoned. The
planks and boards after sawing are placed in large square
piles in the open air, each layer separated by three or four
narrow strips or boards laid in the opposite direction. By
this means a free circulation of air takes place throughout
the pile ; the drying is gradual and thorough, if allowed suf-
ficient time. For ordinary carpentry, two years is considered
enough, but for joinery at least four years should be allotted
to the seasoning. Many processes have been devised to
hasten the evaporation such as kiln-drying, in which the
WARPING. 23
wood is placed in chambers heated by steam or hot air, or
by the employment of vacuum-pumps together with heat.
All are inferior, however, to the open-air seasoning, in that
they cause a rapid drying of the surface and ends, with a
slow or imperfect drying of the interior; thus impairing
both the strength and elasticity of the wood.
It is difficult to give rules for testing wood to determine
whether 'it has been properly seasoned or not. One way is
to push a knife-blade into the wood, and note how much it
sticks when withdrawn. Another is to cut a shaving from
the board, and note its elasticity, brittleness, or strength.
Experienced workmen crush shavings in their hands to de-
termine the character of the wood.
As the wood loses its water it shrinks perceptibly, much
more in the direction of the annual rings than in the direc-
tion of the medullary rays, and very little, if at all, in the
direction of the fibers. If we examine
the end of a log which has been exposed
to the weather, we will find cracks ex-
tending from the center toward the cir-
cumference, and which penetrate from
a few inches to a foot or more into the
log (Fig. 14). These cracks, called
wind-checks, are seen in planks and
boards, and cause the ends to become
waste wood. To prevent this rapid FlG 14 ._ End a of oak .i og ex-
drying, the ends of the logs are tarred wnd d check7 ^ shake.' a '
or painted. If the lumber is piled soon
after sawing, these wind-checks are smaller, and the waste
portion is consequently less.
WARPING.
Because of the unequal shrinking of the wood in drying,
the planks and boards have a natural tendency to warp or curl.
Those cut farthest from the center of the log warp the most,
while those at the center remain nearly flat. Lumber sea-
soned under pressure, such as that exerted in the pile in the
open air, dries straight and true ; but, if it should be resawed
a
EXERCISES IN WOOD-WORKING.
into boards of half the thickness, it will require further sea-
soning to avoid warping. This tendency to warp is sometimes
seen in very old wood ;
for instance, in planing
down an old mahogany
table - top to remove
scratches, what was per-
fectly straight ' and flat
before now warps and
twists to a remarkable
degree. This shows the
construction, lumber of the same
FIG.
15. Warping of planks cut from an unsea-
soned log.
necessity of using, in
thickness in which it has been seasoned.
Another cause which changes the shape of wood is its tend-
ency to absorb moisture, either from the air or the ground.
This makes it necessary to protect exposed surfaces with paint
or varnish. Pieces of work, in process of construction, should
stand endwise and not lie on the floor, even if it seems per-
fectly dry. Lumber in the workshop is kept in racks hang-
ing from the ceiling. These racks are so arranged as to allow
the boards to rest on one edge, and to be separated by vertical
strips. In this manner the boards are easily accessible, and
the seasoning process is continued by the warmth of the room.
PROPERTIES OF WOOD.
Grain. We have seen that wood is composed of long, hol-
low wood cells, or fibers, sometimes accompanied by vessels
of varying diameters. The character and direction of these
fibers constitute what is termed the grain of the wood. As
these fibers separate and break more easily lengthwise than
across, we say that wood splits with the grain. If the fibers
run very straight, the wood is straight-grained; if crooked,
then it is called cross-grained. Many causes affect the regu-
larity of the grain : the stem itself may be crooked, it may
be straight, but the fibers run spirally around it, or there may
be sets of fibers alternating in spiral directions ; branches and
wounds also cause cross-grain.
If the cells' are small and compact, the grain is said to be
PROPERTIES OF WOOD. 25
fine, as in box-wood ; if nearly uniform in size and thickness,
the wood is even-grained, as in maple. The cells may vary
greatly in size and thickness, and have large vessels in the
spring growth, which would give rise to coarse-grained wood,
as in the oak, ash, and chestnut.
The appearance given by the annual rings and medullary
rays to the surface of the wood differs very much with the
kind of wood and the part of the log from which the board
is sawed. Special cuts are made to obtain the best effect of
these markings. To show silver-grain, the face of the board
should be parallel, or nearly so, with the medullary rays.
The birch is an excellent example of this effect. Maple and
ash are frequently seen with a wavy or curled grain. For
veneers, which are about one sixteenth of an inch in thick-
ness, wood with a very irregular grain is selected, such as
walnut roots and knots, and knurls of mahogany. In some
old maple-trees an appearance called bird's-eye, due to a small
circular inflection of the fibers, gives to the wood a fine effect.
Woods in which the grain runs alternately in different
directions, though hard to split and very difficult to work
and finish, usually furnish an ornamented grain, such as
mahogany.
Density. This property depends on the more or less com-
plete thickening of the walls of the wood-cells, and also upon
the number and size of the vessels. Certain operations, such
as turning, carving, and wood-engraving require dense or
close-grained woods.
Porosity. A porous wood has large, thin- walled cells and
many open vessels. Its open grain is easily filled with pre-
serving liquids which adapts it for framing and timber work
generally ; if such a wood is to be finished, the pores must be
filled before a good surface can be obtained. As a rule, porous
woods are soft and light, while dense woods are, hard and
heavy.
Weight and Hardness. It sometimes happens that the en-
tire cell is replaced by the thickened cell-wall, and this, to-
gether with deposits of oily and resinous substances, make
an exceedingly hard and heavy wood. On the contrary, we
26 EXERCISES IN WOOD-WORKING.
have very light woods, even lighter than cork ; these are
composed of thin-walled cells filled with air. Between these
extremes are found many gradations of weight and hardness,
but woods are generally spoken of as hard or soft, and heavy
or light. The hard and heavy woods are stronger and more
durable than the softer and lighter ones.
The weight is expressed by a number, which shows the
weight of the wood compared with the weight of an equal
bulk of water, taken as the standard.
During the process of drying, wood becomes lighter and
harder ; thus, lignum-vitse and most of the palms are quite
soft and easily cut when green, but after drying are worked
with great difficulty.
Strength. The strength of wood depends on peculiar pow-
ers of resisting various forces brought to bear upon it. Thus,
iignum-vitse and the oaks are noted for their stiffness, or
resistance to bending, which is probably due to the interlac-
ing of their fibers. Young hickory, lance-wood, and others
are very elastic, bending readily and returning to their former
position without injury to the structure. Black or swamp
ash and young white oak split easily into long and strong-
strips or bands such as those used for making chair-seats or
baskets. Very little force is required to break the fibers of
whitewood, birch, and mahogany across the grain. Pine,
ash, and maple break easily but with a splintered fracture.
In some palms this splintering occurs to such a degree, that
walking-sticks may be transformed into very dangerous
weapons, which has given rise to laws in some countries re-
stricting their use. Rattan, oak, and hickory, when bent
short, have the individual fibers unbroken, but separated
from each other ; and are therefore tough woods. Hard and
dense woods resist compression, while soft woods yield to
pressure and are indented ; and more so when the pressure
is applied on the sides than on the ends of the fibers. This
compressibility of the softer woods is taken advantage of in
gluing up joints, where the pieces are forced into perfect
contact by the pressure of the screws. To secure a good
joint with hard woods it is necessary to use the greatest care
PROPERTIES OF WOOD. 27
in preparing and cutting the pieces. The cohesion of the
particles of the fibers, when strains are applied lengthwise,
is very great, several tons being required to fracture pine
one inch square.
Color. As the heart-wood becomes lignified, coloring-
matters are deposited within the substance of the cell-wall,
giving to each kind its characteristic colors ; these are ex-
hibited in great variety, including every shade of color be-
tween the white of satin-wood and the black of ebony. In
the same wood there may be variations of tint, or even color,
in the annual rings and medullary rays, enhancing the beauty
of its appearance. The sap-wood receives none of the color-
pigments, and therefore is always light or even white. As
a rule, exposed surfaces, whether varnished or not, become
darker ; and this darkening, besides indicating age, gives to
the surface a more agreeable effect than that of new wood.
It is for this reason, as well as deception, that new cabinet-
work of hard wood is stained to imitate the effects of age.
Color combined with a figured grain constitutes the intrinsic
ornament of wood.
Durability. At great age a slow oxidation of the constitu-
ents of the cell- wall takes place in the interior of the heart-
wood of standing trees, thus rendering the wood softer and
brittle, and an easy prey to the fungi and insects. Dampness,
by promoting fungus growths, is very destructive to cut
timber, few woods withstanding its injurious influence;
especially is this so when there are alternating dampness and
dryness as seen in those portions of a building or structure
in contact with the soil. Most woods if kept dry and pro-
tected from insects with 'paint or varnish, will last for ages, as
illustrated by ancient pieces of furniture. Nearly all woods
are perfectly preserved if kept immersed in water, which is
shown by the wood of vessels that have been sunk for a hun-
dred years or more, and which finds application in laying the
foundations of stone for large buildings and bridges upon
the tops of piles driven below the water-mark. Many woods
like cedar and camphor-wood have within their substance oils
and resins which protect them from the fungi and insect life.
28
EXERCISES IN WOOD-WORKING,
DEFECTS IN WOOD.
Some of the defects found in lumber, as wind-checks,
cross-grain, warping, and improper seasoning, have already
been alluded to. Wood may be shaky (6, Fig. 14), which is a
separation of the annual rings, showing checks or splits,
sometimes including nearly all of the central portion and
extending throughout the length of the stem. No wood fur-
nishes a better example of this than hemlock. This shaky
condition is caused by the swaying from the force of wind,
acting upon trees in open places, along the borders of forests,
and especially those adjoining cleared tracts.
Knots in the wood are imperfections arising from the de-
flection of the fibers which form branches. Near the center
of the stem the fibers are few and the knot - small, but as the
stem enlarges in size the' number of fibers in the branch
increases so that at the circumference of the stem the knots
are largest. The great strength required at the union of
branch and stem is shown by the superi-
or hardness and density of the wood
composing the knot. Dead branches
b give rise to loose and dark-colored knots
(Fig. 16, 6), and the fibers f the stem
that form afterward bend around the
branch, continue up the stem, and pro-
duce cross-grained wood in the vicinity
of the knot. Fast knots are the result
of living branches, and boards contain-
ing them may be used wherever strength
or finish is not required.
Sap-wood. The edges of boards fre-
quently retain a portion of the sap-wood, which must not be
placed in any permanent structure, because of its softness
and tendency to induce decay.
Resin-pockets are spaces between the annual rings of pine
timber, filled completely or in part with resin. These slightly
weaken the board, and if used in any portion of a building
exposed to the warmth of the sun, will exude drops of
FIG. 16. Knots, a, fast
6, loose.
MEASURE AND VALUE OF WOOD. 39
turpentine, even if the surface has been painted or var-
nished.
Decay. Of all the defects in wood, decay or rot is at once
the most prevalent and disastrous to the strength and use-
fulness of the material, and, when begun, will continue until
the whole of the wood is consumed.
Defects in milling are frequent. Lumber may be uneven
in width or thickness. The saw may have torn out fibers in
places, or have cut irregularly, so that, in planing the boards,
marks of the saw remain. When the edges of boards are
not squared, they are termed wany.
MEASURE AND VALUE OF WOOD.
Timber and lumber one inch or more in thickness arc
sold by the square foot, meaning one foot square by one inch
thick, or containing one hundred and forty-four cubic inches.
Boards less than one inch in thickness, and veneers, are sold
by the square foot, face measure. Lumber which is finished
at the mills for special purposes may be sold by the running
foot, or length in feet, as moldings ; or by the piece, as fence-
boards, studs, and many kinds cut to standard sizes. A few
are sold in quantity, as fence-pickets, laths, or a bundle of
shingles, intended to cover a certain area. Many of the more
expensive and fancy woods, such as lignum-vitse and box-
wood, are sold by the pound.
Values of wood vary with supply and demand as well
as with quality and appearance. Durability and a figured
grain are especially sought for. Fashion also, in dictating
the material as well as the style, determines the demand for
the hard woods, particularly those used for furniture and
the interior wood- work of houses. Thus we find a succession
of favorites, each of which, after serving a few years of pre-
ferment, has been set aside to make room for the next. Be-
ginning with mahogany and rose-wood, we note black walnut,
ash, ebony and its imitations, and again mahogany, as having
been the choice, until at the present day, oak, neglected for
many years, is the leading wood.
30 EXERCISES IN WOOD-WORKING.
KINDS OF WOOD.
In this list are given the woods commonly used by car-
penters and joiners, together with their chief characteristics.
Pine Group.
White Pine, commonly called pine, is a rapidly growing
tree in the Northern United States and in Canada. It attains
a large size in favorable soils, and furnishes a light, soft, not
strong wood, with a close and straight grain. The annual
rings are marked by narrow summer growths, and the me-
dullary rays are very fine and numerous. The color is a faint
yellowish brown, darkening with exposure. Its abundance,
the ease with which it is worked, and its power to hold glue,
make its use very extensive, especially in all carpentry-work
where an easily finished wood is desired. It is one of the
best woods for making patterns for casting.
Georgia Pine, of the South Atlantic and Gulf States, is a
large forest tree with smaller annual rings than pine, and
with a broad, dense, resinous, and dark-colored summer
growth, which gives to the wood a well-marked grain. In
radial section the numerous and fine medullary rays are
scarcely visible. The wood is heavy, hard, strong, and dura-
ble, becoming harder and somewhat brittle with age. It is
used for heavy timbers, floors, and, because of its grain,
sometimes as a trimming wood.
The many other species of pine have local or limited use.
Among them the yellow or Jersey pine is perhaps the best
known, as it is largely manufactured into lumber. Its prop-
erties are about intermediate between white and Georgia
pine
Black Spruce grows in about the same regions as white
pine, and furnishes a wood very similar to it, excepting
that it is more resinous. This and white spruce are com-
monly called spruce, and are used extensively for inferior
work.
Hemlock. A species similar to spruce, grows in the North-
ern States. Its wood, which splits or breaks easily, is light,
KINDS OF WOOD. 31
moderately soft, has a coarse, uneven grain, and is frequently
shaky. It holds a nail much better than pine, which fits it
for rougher building material.
White Cedar. Abundant in the Atlantic States, supply-
ing a soft, light, fine-grained, and durable wood, suited
for a variety of purposes where durability rather than
strength is required. The annual growth is of moderate
size, made up of very small wood-cells, traversed by exceed-
ingly fine and numerous medullary rays. It is used in
boat - building, cabinet - work, cooperage, cigar - boxes, and
shingles.
Red Cedar is a small tree of slow growth, widely distrib-
uted in various soils, usually rocky, but reaching its largest
size in swamps. The wood is like white cedar, but more
compact, even-grained, and durable. It is reddish-brown in
color and extensively used in cabinet-work, because of its
strong odor, which repels insects. Its durability makes it
valuable for posts, sills, and other structures in contact with
or near the ground.
Cypress. This tree of the Southern swamps grows to a
great size. It furnishes a most valuable wood, because of its
durability, which is claimed to be superior to that of all
other woods. It is light brown in color, and in structure
similar to white cedar, with larger wood-cells. Its timber is
preferable to pine in trimming brick houses, and in all parts
exposed to the weather. In the South its employment is as
general as that of pine in the North.
Redwood. Of late years the wood of the giant fir-trees of
California has been introduced into the chief lumber mar-
kets of the country. The wood-cells are large, the compact
summer growth constituting about one quarter of the
annual increase. The color is a dull red, the quality very
durable, while the wood shrinks perceptibly in the direc-
tion of the grain. In other respects this wood resembles
pine, and is used for general construction as well as orna-
mentation.
32 EXERCISES IN WOOD-WORKING.
Palm Group.
While in many tropical countries the palms supply the
inhabitants with many necessities, as building-woods, starch,
sugar, fruits, fibers for ropes and cloth ; in temperate cli-
mates the abundance of better material limits the use of the
palm group.
Palms. The numerous kinds differ in height, diameter,
and structure. The fibro-vascular bundles vary in size and
number, are exceedingly hard, and the surrounding pith
either soft or very hard and solid at the outside and soft with
few bundles on the inside. Usually the wood cuts easily
when green, but only with the greatest difficulty when dry.
Besides the use of the palmetto for wharf -piles, some of the
palms are combined in cabinet-work, and used for canes and
handles.
Rattan. A long, slender, trailing palm, furnishing a
tough, flexible material, which enters largely into the manu-
facture of furniture.
Bamboo. A gigantic member of the grass family, grows
in the tropical regions of America and Asia, and has a lim-
ited use in cabinet-work. Its hollow, jointed stem, adapts it
to many inferior uses, such as canes and handles, and when
split and joined in a peculiar way forms the much-prized
fishing-rods.
Oak Group.
Birch. Among the many species of birch, the cherry or
black birch supplies the best lumber. The wood is heavy
and strong, colored brownish-red, with a fine, compact, and
evenly marked grain,, due to the absence of many vessels in
the annual rings, and has very small but visible medullary
rays. It is used in ship-building, turning, and extensively in
cheap furniture.
White Oak is the standard by which the strength, dura-
bility, hardness, and other qualities of the various woods are
compared. It is distributed generally throughout the east-
ern half of the United States, grows to a large size, and fur-
nishes superior timber. Large vessels in the spring growth
occupy from one third to one half of the narrow an-
KINDS OF WOOD. 33
nual rings. The medullary rays are large, thick, and ex-
ceedingly hard. The wood is heavy, hard, strong, diffi-
cult to split radially, coarse-grained, and colored a light
brown. It is used in structures requiring great strength,
and especially in ship-building, cooperage, and carriage-mak>
ing.
Red Oak. A very large forest tree of the United States.
It furnishes a heavy, hard, and strong wood, with a very
coarse grain, due to a large number of vessels of uniform
size crowded into the first half of the annual growth, and
also to the large and thick medullary rays. The wood is
reddish brown, durable, and used extensively for furniture
and cabinet-work generally.
Chestnut. A very large forest tree common in the Atlan-
tic States, having a characteristic coarse-grained wood. The
annual growth is considerable, frequently over half an inch,
in which the vessels are numerous, large in the spring wood,,
but gradually becoming smaller toward the summer growth.
The medullary rays are small and indistinct. The wood is,
light, moderately soft, breaks and splits easily, is remarkably
durable exposed to the weather and not in contact with the
soil.. The tree reaches its best condition at about fifty years
of age, after which it is very liable to decay in the middle of
the heart-wood. It is well adapted for the coarser parts of a-,
building, is used to a small extent in cabinet-work, and ex-
tensively for out-of-door structures.
Beech. A large forest tree growing generally east of the
Mississippi, provides a heavy, hard, and strong wood. It,
has a fine, even grain, is of a light color, and has large me-
dullary rays. It is used to a limited extent for furniture,
but more for implements, especially plane-stocks.
Black Walnut is one of our finest and largest timber-trees,
growing in the central and eastern portions of the United
States. It furnishes long, wide planks and boards of supe-
rior qualities. The wood is moderately heavy and hard,
dark, porous, and marked by a beautiful grain. It is strong,
durable, and not liable to the attacks of insects. The annual
rings contain many vessels, and the medullary rays are ex-
34: EXERCISES IN WOOD-WORKING.
ceedingly small. At one time it was the favorite wood, and
extensively used for internal decoration and fancy-work.
It is still largely used combined with veneers from roots and
knurls of European varieties. Gun-stocks are almost exclu-
sively made of walnut.
Butternut is a small species of walnut, giving a light and
soft wood, with a well-marked grain. Its lumber is short in
length, not liable to split, noted for its resistance to heat and
moisture, and the ease with which it receives paint or polish.
It is used in cabinet-work.
Hickory is a tree of branching habit, found commonly in
the United States. Its wood is heavy, tough, very strong, and
usually cut into planks. The annual rings are indistinct
and crowded with fine vessels, or marked by a narrow zone
of larger vessels. The medullary rays are very broad, nu-
merous, and distinct. The flexibility and toughness of the
wood cause it to be extensively used in the construction of
implements, tools, carriages, etc. Difficulty of working and
liability to the attacks of boring insects prevent its use in
building.
Buttonwood, or sycamore, is the largest tree of the oak
group in the United States. It furnishes a heavy, hard, light-
brown wood, with a fine, close grain. It is readily polished,
easily broken, and difficult to work. Throughout its an-
nual rings are small vessels, very numerous in the spring
growth. The medullary rays are numerous and thick, and
give to the radial section a silver grain similar to that of
beech but more strongly marked. The great liability of the
wood to decay, and its tendency to warp, restrict its use to
structures thoroughly protected from the atmosphere and
moisture.
Ash. A large tree growing in the colder portions of the
United States, furnishes a moderately heavy, hard, strong,
and very elastic wood. The annual rings are compact, with
large vessels in the spring growth. The medullary rays are
numerous, small, and thin. The wood is coarse-grained,
light brown, and extensively used for implements and ma-
chinery, for furniture and cabinet-work. -Its liability to
KINDS OF WOOD. 35
decay, and its brittleness with, age, prevent its use in heavy
work.
Apple. The reddish-colored wood of the familiar fruit
tree, is moderately heavy. and hard, has a very compact
and fine grain. The annual rings are narrow with small
vessels, and the medullary rays are very fine and crowded.
The wood is preferred for tool-handles, turnery, and smok-
ing-pipes.
Pear. In structure the wood of the pear-tree is similar to
that of the apple. It becomes hard and dense when dry,
and yields readily to edge tools. Its almost grainless charac-
ter adapts it for a variety of purposes, particularly carving
and the coarsest kinds of wood-engraving.
Wild Cherry. A tree common in the United States, fur-
nishes a moderately heavy, hard, and durable wood. The
annual rings are wide and evenly filled with small vessels.
The medullary rays are fine, crowded, and light red in color.
The grain is fine and close, and the wood easily polished. It
is brownish red in color, and used extensively for cabinet-
work. After several years the wood becomes very brittle.
Locust. One of the largest forest trees, growing generally
throughout the United States. Its hard, yellowish wood is
composed of very wide annual layers, in which there are
comparatively few and large vessels arranged in rows. The
medullary rays are well marked and numerous. Although it
polishes readily, it is used only to a small extent in cabinet-
work, but finds a demand in exposed structures, where great
durability is necessary, as in ship-building, supports for
buildings, posts, etc. Its hardness, which increases after
manufacture, makes it a favorite with turners.
Sugar-Maple is a timber-tree of large size, growing in the
northern parts of the United States and in Canada, which,
besides furnishing a sap rich in sugar, gives a light-colored,
fine-grained, hard, strong, and heavy wood. Its annual growth
is narrow, with small vessels scattered through it. The medul-
lary rays are small and distinct, giving to the radial surface
a well-marked silver grain. In the older trees, wavy or curled
grain, or the inflection called bird's-eye, may appear, enhanc
36 EXERCISES IN WOOD-WORKING.
ing the beauty and increasing the value of the wood. Were
it not for its want of durability, its hardness and handsome,
silky grain would make it our most valuable wood. It is
used for a great variety of purposes building, implements,
machine-frames, work-benches, furniture, fancy-work, and
turnery. Curled and bird's-eye- maples are frequently sawed
into veneers.
Mahogany. A native tree of the West Indies and Central
America. It is a very large and most valuable tree, furnish-
ing a durable and handsomely marked wood. Its color varies
from yellowish to reddish brown ; its hardness from a mod-
erately to an exceedingly hard wood ; and its grain from
straight to the most crooked contortions. The annual rings
are large, and contain a few large, scattered vessels. The
medullary rays are very fine and crowded. A peculiarity in
the growth of mahogany is the alternating obliquity of the
fibers of one annual layer to those adjoining ; this is some-
times over ninety degrees between fibers four or five layers
apart. The straight-grained varieties have little tendency to
warp, but the cross-grained ones warp and twist to a remark-
able degree. The wood is used for many purposes machine-
frames, work-benches, all kinds of furniture, cabinet-work,
interior finish of dwellings, and patterns.
Lignum-vitae. A West India wood, exceedingly heavy and
hard. The annual rings are almost solid, containing a few
small and scattered vessels. The medullary rays are very
numerous, but difficult to make out. The wood is very resin-
ous, hard to split because of the obliquity of the fibers of the
annual layers, and dark brown in color ; it is soapy to the
touch ; is used for small tools, bowls, and in turnery ; and is
well adapted for block-pulleys.
Basswood is a large tree growing generally throughout
the Northern United States and Canada. It furnishes a light,
soft wood, with the general appearance of pine. The annual
layers are filled with very small vessels, the medullary rays
numerous and distinctly seen in radial sections. Though
not strong, the wood is difficult to split, and has a great tend-
ency to warp. It may be easily bent, thus adapting it to a
KINDS OF WOOD. 37
variety of uses, especially the curved panels of carriages and
sleighs.
Whitewood is the wood of the tulip-tree, a large, straight-
stemmed forest tree, growing in most of the United States.
The wood is light, soft, breaks easily without splintering,
does not split with the grain when dry, shrinks excessively
in drying, and is very liable to warp and twist. The annual
rings are very large, with numerous small vessels through-
out, giving a fine grain. The medullary rays are very nu-
merous and distinct. The cheapness, ease with which it is
worked, and large size of its boards, cause the wood to be
used in carpentry and cabinet-work in many places where
pine is better suited.
Rosewood. The wood of several foreign trees growing in
Brazil, Canary Islands, Siam, and other places. The annual
rings are narrow, almost solid with resinous materials, and
with a few very large, scattered vessels. The medullary rays
are very fine but perceptible on the smoothed surface. The
wood is heavy, hard, brittle, takes a high polish, and has a
characteristic odor and taste. The grain is remarkably hand-
some, those kinds with alternating dark-brown and red mark-
ings being most prized. Besides tool -handles few things are
made of the solid wood ; it is sawed into veneers which are
extensively used in cabinet-work.
Boxwood. A tree growing in Southern Europe and Asia,
furnishes a heavy, hard wood with a peculiarly even, almost
structureless grain. The annual rings are very narrow, with
many small, scattered vessels. The medullary rays are very
fine and numerous. Boxwood is yellowish in color, and is
used for many purposes in turning, model-making, and
particularly in wood-engraving, in which it has no equal.
Ebony. A dark, sometimes jet-black wood, from several
foreign countries, the best coming from the Mauritius. The
wood is heavy, hard, very strong, with an almost solid annual
growth, in which there are very few open vessels. The me-
dullary rays are very fine, but visible. It has an astringent
taste, takes a high polish, and is used for many small articles,
in turnery, and, in cabinet-work.
38 EXERCISES IN WOOD-WORKING.
Table of Woods, with their Chief Qualities compared by Simple Numbers.
COMMON NAME.
Scientific name.
Weight.
Water =
1-00.
Hard-
ness.
Bend-
ing.
Break-
ing.
White Pine
Pinus strobus ,
39
1
5
3
Georgia Pine
P palustris
70
4
10
9
Black Spruce
Picea nigra
46
1
7
4
Hemlock
Tsuga Canadensis
42
2
5
4
White Cedar.
Red Cedar
Chamcecyparis sphceroidea. .
Juniperus Virginiana
33
49
1
4
1
3
1
4
Cypress
Taxodium distichnm
45
2
6
3
Redwood
Sequoia sempervirens
42
1
3
3
Birch
70
7
9
9
White Oak
Ouercus alba .
75
7
6
G
Red Oak
rubra
65
5
7
7
Chestnut .
Castanea vulgaris
45
2
5
4
Beech
J?agus ferruginea
69
6
8
9
Black Walnut. . .
Juglans nigra
61
6
7
5
Butternut
J cinerea
41
2
4
3
Hickory
(Jarya alba
84
9
9
9
Buttonwood
Platanus occidentalis . . .
57
5
5
3
Ash...
Fravinus Americana
65
5
6
5
Wild Cherry . .
Pninus serotina
58
6
5
5
.Locust
73
8
8
10
Su/'ar-^Vfaple
Acer macrophyilum
49
5
4
4
Mahogany .
Swietenia mahogani .
73
10
6
7
Jjignum-vitas
Giiaiacum sanctum
1-14
(28)
5
5
Basswood
TiHa Americana
45
1
5
2
White wood
Liriodendron tulipifera ....
42
2
5
3
WOOD AND IRON.
Before the great advancement in the manipulation of iron
and steel, wood had a much more extended application than
exists at the present day. Structures such as buildings, fur-
niture, and implements, were made entirely of wood; the
pieces were stiffened by wooden braces and the joints fast-
ened by wooden pins. But the superior strength of metal,
and the convenience which attends its use in connection with
wood, have led to great changes in the manner of construc-
tion and the form of the work. Wooden pins and hand-made
nails have given way to machine-cut nails and screws, and
the superior joints obtained by the latter allow the wooden
parts to be made of different kinds and much lighter than
before.
In America, where wood is plentiful and cheap, dwellings
WOOD-WORKING TRADES. 39
and buildings generally are made of this material. In por-
tions of the larger cities where the houses are necessarily
high and crowded, the danger attending the use of such a
readily inflammable substance as wood has led to the adop-
tion of brick and stone for the walls, and metal or slate for
the roofs.
Lightness of weight and the natural beauty of its grain
will always insure the employment of wood in the manufact-
ure of furniture, and for the trim and interior decoration of
houses. To secure lightness and elasticity in implements
and machinery, many parts must be constructed of wood.
Temporary structures, such as scaffolding and the false
work of bridges and trestles, are built of wood, and require
almost as much care in their construction as if intended to
be permanent.
In ship-building, iron and steel have almost supplanted
the employment of wood. Their superior strength and firm-
ness at the joints make safer and faster vessels.
As a direct result of the progress in the manufacture of
iron and steel, most of the wood-working tools and machin-
ery have been greatly modified and improved. This is best
seen among the measuring, boring, and planing tools, which
have so changed that greater accuracy, easier work, and
better finish are now within the power of every workman.
Among the machines may be found appliances for imitating
many of the operations formerly done by hand, and, while
this may ssem to be an encroachment upon the province of
the workman, it must be remembered that the proper care
and adjustment of these machines, and the accurate union of
the pieces shaped by them, necessitate a thorough knowledge
of the manipulation of the hand tools.
WOOD-WORKING TRADES.
While one or two men in a small community may furnish
all the wood and metal work needed by it, in large towns
and cities the great amount and variety of work required
necessitate a division of labor, resulting in numerous trades
or crafts. Some of these are exclusively wood-working,
40 EXERCISES IN WOOD-WORKING.
others metal - working, while a few combine portions of
both.
To follow or employ any one of the trades intelligently
and successfully, the underlying principles governing the use
of all sharp tools must first be thoroughly understood and
acquired by practice. Upon this knowledge as a basis the
numerous details of forms and joints, of arrangement and
adaptation of different materials, must then be accumulated
by years of work and study to produce a mechanic in any
one of the various pursuits.
Carpentry. Of all the wood-working trades carpentry is
the most general. It includes the cutting and framing of
large timbers and rough planks and boards for building
houses, bridges, trestles, piers, ship-frames, and the like.
The form, size, and arrangement of the timbers necessary to
resist the strains are designed by an engineer or architect,
but the details, and especially those of the joints, must be
determined and laid out by the carpenter. The woods made
use of in carpentry are usually pine, hemlock, spruce, oak,
and chestnut. The tools employed are the larger hand-saws,
ax, adz, strong chisels, brace and large bits, hammer, and
mallet ; and for marking, a chalk-line, tape measure, large
steel square, and carpenter's pencil, together with plumb-line
or level ; as a general thing, these complete the outfit.
Joinery differs from carpentry in that the work is smaller
and made smoother; and the form, size, and joints estab-
lished by experience and long usage are constructed to give
a finished appearance as well as strength. All the commoner
arid fancy woods, together with bone, ivory, and some of the
metals, are used in the many branches of joinery. The tools,
besides those of the carpenter, include the finer saws, chisels,
and gouges, the various forms of planes, smaller boring-tools,
and measuring-tools, such as try-squares, bevels, gauges,
compasses, and finely divided rules.
As necessary adjuncts to joinery we have turnery and
carving, with modified forms of chisels and gouges for or-
namental work ; and painting for finishing and preserving
work.
PARASITIC PLANTS. 41
Some of the applications of joinery create distinct trades,
such as cabinet and furniture making ; stair, sash, and door
making; pattern and model making; carriage and boat
building, and cooperage all of which require special woods
and modified forms of tools adapted to the particular and
various forms and joints peculiar to each.
In America there are many mechanics well versed in
both carpentry and joinery of ordinary house-building, and
who are known by the general name of carpenter.
PARASITIC PLANTS.
The forms of plant-life destructive to living trees and
lumber belong to the higher orders of the group Fungi.
These are parasites that is, they do not possess chlorophyl
(the green matter common to the higher orders of plants), and
therefore do not assimilate or digest food for themselves, but
live on the digested and structural material of others. They
are developed from minute spores, grow and decay very
rapidly, and contain a large amount of nitrogen in their
composition.
The structure of these fungi consists of two portions a
tangle of thread-like filaments having somewhat the appear-
ance of the root-hairs in the higher orders of plants, and
which have for their function the absorbing of nutritive
material for the fungus ; and a denser portion composed of
straight filaments, which form on their extremities the spore-
bearing cells.
In developing, the fungus starts from the spore, which
corresponds to the seed of the higher orders. This spore
sends out a long filamentous tube which, as it progresses,
gives off branches, and these in their turn branch until the
tangle of filaments called the mycelium is formed. This my-
celium may have long and separated filaments, as in the
underground portion of mushrooms, or it may have the fila-
ments massed together, as seen in some polyporous fungi
under the bark of trees. When the mycelium has absorbed
sufficient nourishment to produce spores, it sends out the
straight branches usually into the light. The mycelium is
42 EXERCISES IN WOOD-WORKING.
about the same in all the different fungi ; the. variations in
the form and color of the spore-bearing portion, and the char-
acteristics of the spores, giving to each kind its place in clas-
sification.
The exact conditions which cause the spore to develop a
mycelium are not known, but it may be generally stated that
it must find a resting-place containing nutritive elements
peculiarly suited for its growth, and, as accompanying con-
ditions, warmth, moisture, ammonia, and an absence of strong
light.
Some of the fungi obtain their food from the contents of
the living cells of the plant, so that the mycelium destroys
by entering and depleting the sap-wood of the tree. In others
the mycelium secretes a peculiar juice, which has the power
of decomposing the lignin of the heart-wood, and converting
it back into cellulose, which is dissolved and absorbed by the
fungus. The latter destroys by removing those elements
which give to wood its strength, and causes a condition in
the tree or lumber known as decay or rot.
In the heart- wood the vessels and cells facilitate the
growth of the fungus in the direction of the grain, while its
progress across the grain is comparatively
slow. In passing to adjoining cells the
filaments of the mycelium may go through
the pores, or by the solvent action of its
secretion make openings for itself.
The extent to which these fungi will
grow depends on the supply of food mate-
r ^> so that, once established in the stem of
a tree > they may spread until the entire
holes formed by f structure is consumed. If their filaments
pass through the soil, like those of some of
the toadstools, many trees may be affected and destroyed by
one fungus. The innumerable mass of spores given off by
the fungus would seem to predict the entire destruction of
timber-trees, but fortunately this is prevented by the difficul-
ty of satisfying the peculiar requirements necessary for the
development of the spores.
PARASITIC PLANTS.
Among the parasitic fungi those which are especially de-
structive to wood belong to the group HYMENOMYCETES, or
those having naked spores growing on exposed surfaces. In
the agarics, or toadstools, these surfaces are thin, flat plates,
called gills. In the polypores, or tree-fungi, the spore sur-
faces are tubes whose openings constitute the pores. In
Merulius,OY tear-fungus, the spore surfaces are shallow cavi-
ties.
The toadstool (Agaricus melleus) is very destructive to
many trees, including the firs, pines, beech, and oak. Its
mycelium consists of long, dark filaments several inches be-
low the surface of the ground, that gain
access to the wood by attacking the roots
and sending its filaments up into the
stem. The spore-bearing' portion is fre-
quently seen in the autumn at the base of
dead trees ; it is yellowish, and has the
gills extending partly down the stem, on
which is a well-marked ring. Besides
scattering its spores, the danger from this
fungus consists in its power to send fila-
ments through the soil from one tree to
another.
The tree-fungus (Polyporus annosus)
is very destructive to the pines and firs.
Its mycelium is white, silky, and forces
its way through the bark of the roots into
the living cells, and from them into the heart-wood. The
spore-bearing portion may appear on the lower part of the
trunk or upon the roots underground. The porous surface
is turned upward and the spores transported by insects or
burrowing animals from root to root. The Polyporus sul-
phurus is one of the best known of the destructive fungi,
and attacks almost every kind of tree. Its mycelium devel-
ops from spores which lodge in the stump of broken or
sawed branches, and passes downward into the stem con-
suming the tissue as it goes. Jts sporing portion is bright
yellow on the under or porous side and red above, usually
FIG. 18. Toadstool, a,
stem ; ft, umbrella top ;
c, ring, attached to Jhe
top before it expands ;
d, gills ; e, filaments
forming the mycelium.
44 EXERCISES IN WOOD- WORKING.
projecting from the decayed stump of the branch or in ad-
vanced cases from the side of the stem.
P. pini is similar to the P. sulphurus,
and is a wound-parasite on the pines.
P. fulvus is also a pine-tree fungus, pe-
culiar in its action, in that it does not dis-
solve the lignified parts of the cell, but the
thin membranous substance which unites
the cells, thus setting the cells free. P.
dryadeus acts in a similar way in oak-trees.
FIG. 19. - Poiypore MeruUus Ictcrymans affects pine and
f