THE EXHAUSTION OF THE FOREST.
The exhaustion of the forest in the United States is due to two main
causes: (1) Fire, and (2) Destructive Lumbering.
FIRE.
It is not commonly realized that forest fires are almost entirely the
result of human agency. When cruisers first began to locate claims in
this country, practically no regions had been devastated by fire. Now
such regions are to be seen everywhere. Altho lightning occasionally
sets fire to forests, especially in the Rocky Mountains, the losses
from this cause are trifling compared with the total loss.
[Illustration: Fig. 104. Slash, Left in the Woods, and Ready to Catch
Fire. _U. S. Forest Service._]
_Opportunities for fire._ There are a number of facts that make the
forest peculiarly liable to fire. Especially in the fall there are
great quantities of inflammable material, such as dry leaves, twigs,
and duff lying loose ready for ignition. The bark of some trees,
as "paper birch," and the leaves of others, as conifers, are very
inflammable. It follows that fires are more common in coniferous than
in deciduous forests. After lumbering or windfalls, the accumulated
"slash" burns easily and furiously, Fig. 104. Moreover a region once
burned over, is particularly liable to burn again, on account of the
accumulation of dry trunks and branches. See Fig. 107.
Long dry seasons and high wind furnish particularly favorable
conditions for fire. On the other hand, the wind by changing in
direction may extinguish the fire by turning it back upon its track.
Indeed the destructive power of fires depends largely upon the wind.
[Illustration: Fig. 105. Forest Fire. _U. S. Forest Service._]
_Causes of fire._ Forest fires are due to all sorts of causes,
accidental and intentional. Dropped matches, smouldering tobacco,
neglected camp fires and brush fires, locomotive sparks, may all be
accidental causes that under favorable conditions entail tremendous
loss. There is good reason to believe that many forest fires are set
intentionally. The fact that grass and berry bushes will soon spring
up after a fire, leads sheep men, cattle and pig owners, and berry
pickers to set fires. Vast areas are annually burned over in the
United States for these reasons. Most fires run only along the surface
of the ground, doing little harm to the big timber, and if left alone
will even go out of themselves; but if the duff is dry, the fire may
smoulder in it a long time, ready to break out into flame when it
reaches good fuel or when it is fanned by the wind, Fig. 105. Even
these ground fires do incalculable damage to seeds and seedlings, and
the safest plan is to put out every fire no matter how small.
[Illustration: Fig. 106. Burned Forest of Engelmann Spruce.
Foreground, Lodgepole Pine Coming in. _U. S. Forest Service._]
Altho it is true that the loss of a forest is not irremediable because
vegetation usually begins again at once, Fig. 106, yet the actual
damage is almost incalculable. The tract may lie year after year,
covered with only worthless weeds and bushes, and if hilly, the region
at once begins to be eroded by the rains.
After the fire, may come high winds that blow down the trunks of the
trees, preparing material for another fire, Fig. 107.
[Illustration: Fig. 107. Effect of Fire and Wind. Colorado. _U. S.
Forest Service._]
The statistics of the actual annual money loss of the timber burned
in the United States are not gathered. In 1880 Professor Sargent
collected much information, and in the census of that year (10th
Census, Vol. IX) reported 10,000,000 acres burned that year at a value
of $25,000,000.
In 1891, the Division of Forestry collected authentic records of
12,000,000 acres burned over in a single year, at an estimated value
of $50,000,000.
In the Adironacks in the spring of 1903, an unprecedentedly dry
season, fire after fire caused a direct loss of about $3,500,000.
In 1902, a fire on the dividing line between Washington and Oregon
destroyed property amounting to $12,000,000. Within comparatively
recent years, the Pacific Coast states have lost over $100,000,000
worth of timber by fire alone.
During September, 1908, forest fires raged in Minnesota, Michigan,
Wisconsin, Maine, New York and Pennsylvania. The estimates of loss
for northern Michigan alone amounted to $40,000,000. For two weeks
the loss was set at $1,000,000 a day. The two towns of Hibbing and
Chisholm were practically wiped out of existence, and 296 lives were
lost.
Certain forest fires have been so gigantic and terrible as to become
historic.
One of these is the Miramichi fire of 1825. It began its
greatest destruction about one o'clock in the afternoon of
October 7th of that year, at a place about sixty miles
above the town of Newcastle, on the Miramichi River, in New
Brunswick. Before ten o'clock at night it was twenty miles
below New Castle. In nine hours it had destroyed a belt of
forest eighty miles long and twenty-five miles wide. Over more
than two and a half million acres almost every living thing
was killed. Even the fish were afterwards found dead in heaps
on the river banks. Many buildings and towns were destroyed,
one hundred and sixty persons perished, and nearly a thousand
head of stock. The loss from the Miramichi fire is estimated
at $300,000, not including the value of the timber. (Pinchot,
Part 1. p. 79-80.)
Of such calamities, one of the worst that is on record is that
known as the Peshtigo fire, which, in 1871, during the same
month, October, when Chicago was laid in ashes, devastated the
country about the shores of Green Bay in Wisconsin. More than
$3,000,000 worth of property was burnt, at least two thousand
families of settlers were made homeless, villages were
destroyed and over a thousand lives lost. (Bruncken, p. 110.)
The most destructive fire of more recent years was that which
started near Hinckley, Minn., September 1, 1894. While the
area burned over was less than in some other great fires, the
loss of life and property was very heavy. Hinckley and six
other towns were destroyed, about 500 lives were lost, more
than 2,000 persons were left destitute, and the estimated loss
in property of various kinds was $25,000,000. Except for the
heroic conduct of locomotive engineers and other railroad men,
the loss of life would have been far greater.
This fire was all the more deplorable, because it was wholly
unnecessary. For many days before the high wind came and drove
it into uncontrollable fury, it was burning slowly close to
the town of Hinckley and could have been put out. (Pinchot,
Part I, 82-83.)
One of the most remarkable features of these "crown fires," is the
rapidity with which they travel. The Miramichi fire traveled nine
miles an hour.
To get an idea of the fury of a forest fire, read this description
from Bruncken. After describing the steady, slow progress of a duff
fire, he proceeds:
But there comes an evening when nobody thinks of going to bed.
All day the smoke has become denser and denser, until it is no
longer a haze, but a thick yellowish mass of vapor, carrying
large particles of sooty cinders, filling one's eyes and
nostrils with biting dust, making breathing oppressive. There
is no escape from it. Closing windows and doors does not bar
it out of the houses; it seems as if it could penetrate solid
walls. Everything it touches feels rough, as if covered with
fine ashes. The heat is horrible altho no ray of sunshine
penetrates the heavy pall of smoke.
In the distance a rumbling, rushing sound is heard. It is the
fire roaring in the tree tops on the hill sides, several miles
from town. This is no longer a number of small fires, slowly
smouldering away to eat up a fallen log; nor little dancing
flames running along the dry litter on the ground, trying to
creep up the bark of a tree, where the lichens are thick and
dry, but presently falling back exhausted. The wind has risen,
fanning the flames on all sides, till they leap higher and
higher, reaching the lower branches of the standing timber,
enveloping the mighty boles of cork pine in a sheet of flame,
seizing the tall poles of young trees and converting them
into blazing beacons that herald the approach of destruction.
Fiercer and fiercer blows the wind, generated by the fire
itself as it sends currents of heated air rushing upward into
infinity. Louder and louder the cracking of the branches as
the flames seize one after the other, leaping from crown to
crown, rising high above the tree tops in whirling wreaths
of fire, and belching forth clouds of smoke hundreds of feet
still higher. As the heated air rises more and more, rushing
along with a sound like that of a thousand foaming mountain
torrents, burning brands are carried along, whirling on across
the firmament like evil spirits of destruction, bearing the
fire miles away from its origin, then falling among the dry
brush heaps of windfall or slashing, and starting another fire
to burn as fiercely as the first. * * *
There is something horrible in the slow, steady approach of
a top fire. It comes on with the pitiless determination of
unavoidable destiny, not faster than a man can walk. But there
is no stopping it. You cannot fight a fire that seizes tree
top after tree top, far above your reach, and showers down
upon the pigmy mortals that attempt to oppose it an avalanch
of burning branches, driving them away to escape the torture
and death that threatens them. (Bruncken, _American Forests
and Forestry_, 106-109.)
[Illustration: Fig. 108. Fighting Forest Fire. _U. S. Forest
Service._]
Real forest fires are not usually put out; men only try to limit them.
A common method of limitation is to cut trenches thru the duff so that
the fire cannot pass across, Fig. 108. In serious cases back fires are
built on the side of the paths or roads or trenches toward the fire,
in the expectation that the two fires will meet. In such cases great
care has to be taken that the back fire itself does not escape. Small
fires, however, can sometimes be beaten out or smothered with dirt and
sand, since water is usually unavailable.
[Illustration: Fig. 109. Fire Lane. Worcester Co., Mass. _U. S. Forest
Service._]
But "an ounce of prevention is worth a pound of cure." One of the best
of these preventions is a system of fire lanes. Even narrow paths of
dirt will stop an ordinary fire. Roads, of course, are still better.
Systems of fire lanes, Fig. 109, are made great use of in Europe
and British India. Belts of hardwood trees are also cultivated along
railways, and to break up large bodies of conifers.
If in lumbering, the slash were destroyed or even cut up so as to lie
near the ground and rot quickly, many fires would be prevented.
Some states, as New York, have a fairly well organized system of fire
wardens, who have the authority to draft as much male help as
they need at $2.00 a day to fight forest fires. Unfortunately
"ne'er-do-wells" sometimes set fire to the woods, in order to "make
work" for themselves. Much preventive work is also done by educating
the public in schools and by the posting of the fire notices,[1] Fig.
110.
[Illustration: Fig. 110. Look out for Fire. Rules and Laws.]
DESTRUCTIVE LUMBERING.
How the reckless and destructive methods of lumbering common in
America came into vogue, is worth noting.[2]
The great historical fact of the first half century of our country
was the conquest of the wilderness. That wilderness was largely an
unbroken forest. To the early settler, this forest was the greatest
of barriers to agriculture. The crash of a felled tree was to him a
symbol of advancing civilization. The woods were something to be got
rid of to make room for farms, Fig. 111. In Virginia, for example,
where the soil was soon exhausted by tobacco culture and modern
fertilizers were unknown, there was a continual advance into the woods
to plant on new and richer land. The forest was also full of enemies
to the settler, both animals and Indians, and was a dreaded field for
fire. So there grew up a feeling of hate and fear for the forest.
[Illustration: Fig. 111. Forest Giving Place to Farm Land. North
Carolina. _U. S. Forest Service._]
More than that the forest seemed exhaustless. The clearings were at
first only specks in the woods, and even when they were pushed farther
and farther back from the seacoast, there was plenty of timber beyond.
The idea that the area of this forest could ever be diminished
by human hands to any appreciable extent so that people would
become afraid of not having woodland enough to supply them
with the needed lumber, would have seemed an utter absurdity
to the backwoodsman. * * * Thus the legend arose of the
inexhaustible supply of lumber in American forests, a legend
which only within the last twenty years has given place to
juster notions. (Bruncken, p. 57.)
This tradition of abundant supply and the feeling of hostility to the
forest lasted long after the reasons for them had disappeared. When
we remember that every farm in the eastern United States, is made from
reclaimed forest land and that for decades lumber was always within
reach up the rivers, down which it was floated, it is not strange that
reckless and extravagant methods of cutting and using it prevailed.
Following the settler came the lumberman, who continued the same
method of laying waste the forest land. The lumber market grew slowly
at first, but later developed by leaps and bounds, until now the
output is enormous.
Lumbering in America has come to be synonymous with the clearing off
of all the marketable timber, regardless of the future. It treats the
forest as tho it were a mine, not a crop, Fig. 112. Since 1880 the
total cut has been over 700,000,000 feet, enough to make a one inch
floor over Vermont, Massachusetts, Connecticut, Rhode Island and
Delaware, or one-half of the State of New York, an area of 25,000
square miles.
[Illustration: Fig. 112. Redwood Forest Turned Into Pasture.
California. _U. S. Forest Service._]
Other countries, too, have devastated their forests. Portugal has
a forest area of only 5 per cent. of the total land area, Spain and
Greece, each 13 per cent., Italy 14 per cent. and Turkey 20 per cent.
Whether the destruction of the American forests shall go as far
as this is now a live question which has only just begun to be
appreciated.
Another reason for the reckless American attitude toward the forest is
the frequency and severity of forest fires. This has led to the fear
on the part of lumbermen of losing what stumpage they had, and so they
have cleared their holdings quickly and sold the timber. Their motto
was "cut or lose."
A third incentive to devastative methods was the levy of what were
considered unjust taxes.
Hundreds of thousands of acres in the white pine region,
notably in Michigan, Wisconsin, and Minnesota, have been cut
over, abandoned, sold for taxes, and finally reduced by fire
to a useless wilderness because of the shortsighted policy of
heavy taxation. To lay heavy taxes on timber land is to set
a premium on forest destruction, a premium that is doing
more than any other single factor to hinder the spread of
conservative lumbering among the owners of large bodies
of timber land. * * * Heavy taxes are responsible for the
barrenness of thousands of square miles which should never
have ceased to be productive, and which must now lie fallow
for many decades before they can be counted again among the
wealth-making assets of the nation. (Pinchot, _Agric. Yr.
Bk._, 1898, pp. 184-185.)
On the treatment of the questions of fire and taxes depends
the future of American forest industries. (Bruncken, p. 226.)
Undoubtedly much waste has been caused by sheer ignorance of forest
conditions and methods, which, if followed, would secure successive
crops instead of one, but it is safe to say that the desire for
immediate profits has been the dominant cause of reckless lumbering.
So short-sighted has the policy of private owners proved itself, that
it is a question whether any large extent of forest land can safely
be left in private hands. No individual lives long enough to reap more
than one forest crop. Only corporations and States can be expected
to have an interest long enough continued to justify the methods of
conservative lumbering.
As a matter of fact, nearly one-half of the privately owned timber
of the United States is held by 195 great holders, the principal ones
being the Southern Pacific Company, the Weyerhauser Timber Company,
and the Northern Pacific Railway Company, which together own nearly 11
per cent. of the privately owned forests of the country. These large
holders are cutting little of their timber, their object, however,
being not so much to conserve the forests as to reserve to themselves
the incalculable private profits which are expected to come with the
future enormous increase in the value of timber.
Over against this policy, stands that of the United States Forest
Service of increasing the area of the National Forests in order to
conserve them for the public welfare. The pity is that the government
ever let the forests pass out of its hands. Only forty years ago
seventy-five per cent. of the timber now standing was publicly owned.
Now about eighty per cent. of it is privately owned. In the meanwhile
its value has increased anywhere from ten to fifty fold, according to
locality.[3] Some large corporations, however, like the Pennsylvania
Railroad, the Kirby Lumber Company, of Texas, and the International
Paper Company, have entered upon a policy of conservative lumbering.
Of the actual practices which distinguish destructive lumbering, a few
may be cited. Stumps are cut too high and tops too low. Good lumber is
wasted on lumber roads and bridges, Fig. 113. Saplings are torn down
in dragging out logs. Slash is left in condition to foster fires and
left with no shade protection. Seedlings are smothered with slash.
Seed trees are all cut out leaving no chance for reproduction. Only
poorer sorts of trees are left standing, thus insuring deterioration.
Paper pulp cutting goes even farther than lumbering, and ordinarily
leaves nothing behind but a howling wilderness.
[Illustration: Fig. 113. Red Spruce Used in Building Skidway, and Left
in the Woods. Hamilton Co., New York.]
The production of turpentine from the long-leaf pine, Fig. 114, at
the annual rate of 40,000 barrels has meant the devastation of 70,000
acres of virgin forest.
[Illustration: Fig. 114. Turpentine Boxing, Cup System. Georgia. _U.
S. Forest Service._]
In view of this wholesale destruction it becomes of interest to know
how much still remains of the timber supply of the United States.
The latest and most authoritative estimate of standing timber
in continental United States, excluding Alaska, gives a total of
2,800,000,000 M feet B.M.,[4] of which 2,200,000,000 M feet are
privately owned, about 539,000,000 M feet are in the National Forests
(Fig. 119, p. 271,) and 90,000,000 M feet are on the unreserved public
lands, National parks, State lands and Indian reservations.
Earlier estimates were hardly more than guesses. For example the
census of 1880 estimated the stumpage of the U. S. at 856,290,100 M
feet, while the census of 1900 gives a total of 1,390,000,000 M feet.
The discrepancy appears still greater when it is remembered that in
the meantime 700,000,000 M feet were cut. Of this amount 500,000,000 M
feet were of conifers or 80,000,000 M feet more than were included in
the estimate of 1880. The simple fact is of course that the earlier
estimates were gross underestimates, due to the fact that they were
based on entirely inadequate data, and therefore can not be used to
obscure the now unquestionable fact that the timber supply of this
country is surely and rapidly melting away.
The Forest Service estimates that the present annual cut of saw timber
is about 50,000,000 M feet. At this rate the present stand would last
about 55 years and the privately owned timber only 44 years. This
estimate does not allow for growth and decay.
While the population of the United States increased 52 per cent. from
1880 to 1900, during the same period the lumber-cut increased 94 per
cent. In other words the yearly increase in use is 20 to 25 per
cent. per capita, that is, fast as the population grows, the lumber
consumption increases nearly twice as fast. This increase in the
lumber-cut far overbalances the growth of trees.
It is also to be remembered that this increase in the use of lumber is
in spite of the enormous increase of substitutes for lumber, such as
brick, cement and steel for building, and steel for bridges, vehicles,
fences, machinery, tools, and implements of all kinds.
How lavishly we use lumber may further be appreciated from the fact
that we consume 260 cubic feet[5] per capita, while the average for
13 European countries is but 49 cubic feet per capita. In other words
every person in the U. S. is using five times as much wood as he would
use if he lived in Europe. It is estimated that on an average each
person in this country uses annually the product of 25 acres of
forest. _The country as a whole, cuts every year, between three and
four times more wood than all the forests grow in the meantime._
By contrast, the principal countries of Europe, cut just the annual
growth, while Russia, Sweden and Japan, cut less than the growth. In
other words, the 2,800,000,000,000 feet B.M. of the stumpage of the
United States is a capital which is constantly drawn upon, whereas,
the 944,700,000,000 board feet of the forest of the German Empire is
a capital which is untouched but produces annually 300 board feet per
acre.
[Illustration: Fig. 115. (Lumber Production by Regions, 1907).
Southern States include: Virginia, North Carolina, South Carolina,
Georgia, Florida, Alabama, Mississippi, Louisiana, Arkansas, Texas and
Oklahoma.
Pacific States include: Washington, Oregon and California.
North Atlantic States include: New England, New York, Pennsylvania,
New Jersey, Delaware, and Maryland.
Lake States include: Michigan, Wisconsin, and Minnesota.
Central States include: Ohio, West Virginia, Kentucky, Tennessee,
Indiana, Illinois, and Missouri.
Rocky Mountain States include: Montana, Idaho, Wyoming, Nevada, Utah,
Colorado, Arizona, and New Mexico.]
One striking evidence of the decrease of the timber supply is the
shifting of its sources. Once the northeastern States produced over
half of the lumber product. They reached their relative maximum in
1870 when they produced 36 per cent. At that time the Lake States
produced about 24 per cent. By 1890 the Lake States came to their
maximum of 36 per cent. Today the southern States are near their
maximum with 41 per cent., but the center will soon shift to the
Pacific States. Their product rose from less than 10 per cent. of the
whole in 1900 to 17 per cent. in 1908, Figs. 115 and 116. When
that virgin forest has been cut off, there will be no new region
to exploit; whereas, heretofore, when a region was exhausted, the
lumbermen have always had a new one to which to move. At the
annual meeting of the Northern Pine Manufacturers' Association in
Minneapolis, Minn., January 22, 1907, Secretary J. E. Rhodes made this
striking statement:
Since 1895, 248 firms, representing an annual aggregate
output of pine lumber of 4-1/4 billion feet, have retired from
business, due to the exhaustion of their timber supply. Plants
representing approximately 500 million feet capacity, which
sawed in 1906, will not be operated in 1907.
The shifting of the chief sources of supply has, of course,
been accompanied by a change in the kinds of lumber produced.
There was a time when white pine alone constituted one-half
of the total quantity. In 1900 this species furnished but 21.5
per cent., in 1904 only 15 per cent., of the lumber cut.[6] We
do not use less pine because we have found something better,
but because we have to put up with something worse.
[Illustration: Fig. 116. (Lumber Production by States).]
The present annual cut of southern yellow pine is about 13-1/4 million
M feet, or a little less than one-third of the total cut of all the
species. At the present rate of consumption, it is evident that within
ten or fifteen years, there will be a most serious shortage of it.
Meanwhile the cut of Douglas fir on the Pacific coast has increased
from 5 per cent. of the total lumber cut in 1900 to 12 per cent. in
1905. This increase is in spite of the fact, already noted (p. 262)
that the great timber owning companies of the northwest are holding
their stumpage for an expected great increase in value.
Another evidence of shortage is the almost total disappearance of
certain valuable species. Hickory, which once made American buggies
famous, is getting very scarce, and black walnut once commonly used
for furniture, is available now for only fine cabinet work, veneers,
gun stocks, etc. Hardwoods that are fit for the saw are rapidly
decreasing. The hardwood cut of 1900 of 8,634,000 M feet diminished in
1904 to 6,781,000 M feet.
[Illustration: Fig. 117. (Lumber Production by Species).]
A still further evidence of the decreasing supply, is the rising scale
of prices. White pine, which sold for $45.00 per M during 1887-1892,
sold for $100.00 f.o.b. N. Y., Jan. 1, 1911. Yellow poplar went up in
the same period, 1887-1911, from $29.00 to $63.00. Yellow pine rose
from $18.00 in 1896 to $47.00 in 1911, and hemlock, the meanest of all
woods, from $11.50 in 1889 to $21.00 in 1911, Fig. 118.
[Illustration: Fig. 118. Wholesale lumber prices, 1887-1911.
The qualities of lumber shown in the above chart are as follows:
White Ash, 1st and 2d, 1" and 1-1/2" x 8" and up by 12'-16'.
Basswood, 1st and 2d, 1" x 8" and up by x 00".
White Oak, quarter-sawed, 1st and 2d, all figured, 1" x 6" and up x
10'-16'.
Yellow poplar, 1st and 2d, 1" x 7"-17" x 12'-16'.
Hemlock, boards
Spruce, No. 1 and clear, 1" and 1-1/4" x 4" x 13'.
White pine, rough uppers, 1" x 8" and up x 00'.
Yellow pine, edge grain flooring. The curve is approximately correct,
for the standard of quality has been changed several times.]
It is to be remembered, moreover, that as the timber in any region
becomes scarcer, the minimum cutting limit is constantly lowered, and
the standard of quality constantly depreciated. Poorer species
and qualities and smaller sizes, which were once rejected, are now
accepted in the market. For example, 6 inches is now a common cutting
diameter for pine and spruce, whereas 12 inches was the minimum limit,
and on the Pacific coast there is still nothing cut below 18 inches.
This cutting of smaller sizes is largely due to the capacious maw of
the pulp mill, which swallows even the poorest stuff. Altho the amount
of wood used for paper pulp is small in comparison with the total
lumber production, being about 5.4 per cent., yet this cutting
of young growth keeps the forest land devastated. In 1906 nearly
9,000,000 tons of wood were used for paper pulp in the United States.
No one who is at all familiar with the situation doubts for an
instant that we are rapidly using up our _forest capital_. In
fact it is unquestionably safe to say that our present annual
consumption of wood in all forms is _from three to four times
as great as the annual increment of our forests_. Even
by accepting the highest estimate of the amount of timber
standing we postpone for only a few years the time when there
must be a great curtailment in the use of wood, if the present
methods of forest exploitation are continued. Every indication
points to the fact that under present conditions the maximum
annual yield of forest products for the country as a whole has
been reached, and that in a comparatively short time, there
will be a marked decrease in the total output, as there is now
in several items. (Kellogg, _Forestry Circular_, No. 97, p.
12.)
On the other hand, it is to be remembered that there are influences
which tend to save and extend the forest area. These will be
considered in the next chapter, on the Use of the Forest.
[Footnote 1:
LOOK OUT FOR FIRE!
RULES AND LAWS.
Fires for clearing land near a forest must not be started
until the trees are in full leaf. Before lighting such fires
three days' notice, at least, must be given to the Firewarden
and occupants of adjoining lands. After such fires are
lighted, competent persons must remain to guard them until the
fire is completely extinguished, and the persons starting such
fires will be held responsible for all damages notwithstanding
notice had been given to the Firewarden.
Fires will be permitted for the purposes of cooking, warmth
and insect smudges, but before such fires are kindled,
sufficient space around the spot where the fire is to be
lighted must be cleared from all combustible material; and
before the place is abandoned, fires so lighted must be
thoroly quenched.
All fires other than those hereinbefore mentioned are
absolutely prohibited.
Hunters and smokers are cautioned against allowing fires to
originate from the use of firearms, cigars and pipes.
Especial care should be taken that lighted matches are
extinguished before throwing them down.
All persons are warned that they will be held responsible for
any damage or injury to the forest which may result from their
carelessness or neglect.
Girdling and peeling bark from standing trees on state land is
prohibited. Fallen timber only may be used for firewood.
All citizens are requested to report immediately any cases
which may come to their knowledge of injury to woodlands
arising from a violation of these rules.
Then follow quotations from the laws of the state of New York.
]
[Footnote 2: For the common methods of logging see _Handwork
in Wood_, Chapter I.]
[Footnote 3: See Summary of Report of the Commissioner of
Corporations on the Lumber Industry. February 13, 1911.
Washington, D. C.]
[Footnote 4: A board foot is one foot square and one inch
thick.]
[Footnote 5: 167 cubic feet equal about 1000 board feet.]
[Footnote 6: _Forestry Circular_, No. 97.]
THE EXHAUSTION OF THE FOREST
REFERENCES:[A]
(1) Fires.
Bruncken, pp. 183-207.
Pinchot, _Agric. Yr. Bk._, p. 189.
Suter, _For. Circ._ No. 36.
U. S. Tenth Census, Vol. IX, p. 491 ff.
Pinchot, _Primer_, pp. 77-88.
Roth, _First Book_, pp. 104-112.
Sterling, _Agric. Yr. Bk._, 1904, p. 133.
(2) Destructive Lumbering.
The Settler's Tradition.
Bruncken, pp. 40-59, 94.
Roth, _First Book_, pp. 41-45.
Pinchot, _Primer_, II, p. 82.
Taxation.
_For. and Irr._, April, '06.
Pinchot, _Agric. Yr. Bk._, 1898, p. 184.
Reckless Practices.
Pinchot, _Primer_ II, 42-47.
Pinchot, _Agric. Yr. Bk._, 1898, p. 184.
Pinchot, _For. Circ._, No. 25, p. 11.
Price, _Agric. Yr. Bk._, 1902, p. 310.
Fox, _For. Bull._, No. 34, p. 40.
Peters, _Agric. Yr. Bk._, 1905, pp. 483-494.
Graves, _Agric. Yr. Bk._, 1899, p. 415.
Suter, _For. Bull._, 26, pp. 58, 69, 76.
Mohr, _For. Bull._ No. 13, p. 61.
Bruncken, pp. 90-98.
The Timber Supply.
Kellogg, _For. Circ._, No. 97 ...
Zon, _For. Bull._, No. 83.
Fernow, _Economics_, pp. 35-45.
Report of the Commissioner of Corporations on the Lumber Industry.
Part I, Feb. 13, 1911.
[Footnote A: For general bibliography, see p. 4.]
CHAPTER VIII.
THE USE OF THE FOREST.
Man's relation to the forest has not been entirely destructive and
injurious. He has exerted and is more and more exerting influences
which while still enabling him to use the forest, also preserve
and improve it. These activities may all be included under the term
Forestry.
The objects of modern forestry then are threefold: 1. The
_utilization_ of the forest and its products, the main object; 2. The
_preservation_ of the forest, _i.e._, its continued reproduction; 3.
The _improvement_ of the forest.
UTILIZATION.
The uses of the forest are threefold: (1) Protective, (2) Productive,
and (3) Esthetic.
(1) _Protective._ The forest may be used as a protection against
floods, wind, shifting sand, heat, drought, etc. The National Forests
of the United States, Fig. 119, with the state forests, which include
one-fifth of the total forest area, are largely treated as "protection
forests" to maintain the head waters of streams, Fig. 120, used for
irrigation, for power or for commerce. The attempt now being made to
reserve large areas in the White Mountains and southern Appalachians
is chiefly for this purpose of protection.
[Illustration: Fig. 119. National Forests in the United States.]
A comparison of Figs. 120 and 121 shows clearly the difference between
a region protected by forest and one unprotected.[1]
[Illustration: Fig. 120. A Protection Forest, Maintaining the
Headwaters of Streams. North Carolina. _U. S. Forest Service._]
[Illustration: Fig. 121. Hillside Erosion. North Carolina. _U. S.
Forest Service_]
(2) _Productive._ All practical foresters have as their first aim
the _yield_ of the forest. This distinguishes forestry from landscape
architecture, the object of which may equally be the preservation and
improvement of a given tract. The crop to be produced is as truly the
prime concern of the forester as the raising of agricultural crops is
the prime concern of the farmer. It is for this reason that forestry
is said to be the same thing as conservative lumbering, Fig. 122.
The prejudice of lumbermen against forestry has arisen from a
misunderstanding of its aim. Its aim is not to prevent the cutting
down of trees, but to direct their cutting in such ways that in the
future there will still be trees to cut. "Thru use to a greater use,"
is the motto of the Forest Service. The difference between destructive
lumbering and conservative lumbering is that the former cuts one crop
regardless of the future; while the latter plans to cut crop after
crop indefinitely. In other words, in conservative lumbering, the
trees to be cut are not selected solely with reference to their
immediate market value. Not one crop, but many, is the forester's
motto.
[Illustration: Fig. 122. Conservative Lumbering. Black Hills National
Forest, South Dakota. Note the brush, cord-wood, and logs piled
separately,--a fine clean-up. Nothing cut below 12" diameter. _U. S.
Forest Service._]
So long as the supply seemed exhaustless, forests might be and were
treated as mines are, _i.e._, exploited for the sake of immediate
profit; but now that lumbermen begin to realize that the end of the
supply is in sight, more conservative methods are being adopted. We
cannot afford to kill the goose that lays the golden eggs. In order
then to obtain as rich harvests as possible, the modern forester makes
use of various methods, some negative, some positive.
Waste is avoided in all possible ways, stumps are cut low and tops
high on the trunk, first class trees are not used for skids, bridges,
roads, etc., care is taken in "falling" trees and in dragging out
logs, that they will not injure other trees. Just as economical
disposal of the log has already been carried to a high degree of
perfection in the saw-mill, (see _Handwork in Wood_, Chapter II,) so
one object of forestry is to carry this economy back into the woods.
One of the underlying ideas in conservative lumbering is that the
"yield," _i.e._, the amount of wood taken out of a healthy forest
in a given time, shall be equal to the amount grown during the same
period. If less is taken out than grows, some trees will overmature
and decay; if more is taken out than grows, the forest will ultimately
be exhausted.
This principle may be carried out in a number of ways; but in any case
it is necessary to know how fast the forest is reproducing itself, and
this is one of the functions of the forester. The United States
Forest Service makes a definite offer of cooperation with farmers and
lumbermen and owners of forests to provide them with skilled foresters
for direction in this matter.
In the United States, the most practicable way of determining the
yield is by area, _i.e._, a certain fraction of a forest is to be
cut over once in a given length of time, a year or longer. The time
between two successive cuttings on the same area must be long enough
to allow the young trees left standing to ripen.
In a word, conservative lumbering involves (1) the treatment of the
forest as a source of crops, (2) systematic gathering, and (3) young
growth so left as to replace the outgo.
The important place that forests fill in the national economy may
be realized partly by the citation of a few facts as to the forest
products. The lumber industry is the fourth in value of products
among the great manufacturing industries of the United States,
being exceeded only by the iron and steel, the textile, and the meat
industries. It turns out a finished product worth $567,000,000.00. And
yet lumber constitutes only about one-half of the value of the total
output of forest products. Its annual value is three-fourths of a
billion dollars, ($666,641,367 in 1907,) while the annual value of
wood fuel, is $350,000,000. More than two-thirds of the people burn
wood for fuel. The next largest single item in the list is shingles
and laths, $32,000,000. (See _Forestry Bulletin_ No. 74, p. 7.)
Outside of food products, no material is so universally
used and so indispensable in human economy as wood. (Fernow,
_Econ._, p. 21.)
The importance of forest products may also be learned from a mere list
of the varied uses to which they are put. Such a list would include:
fuel, wood and charcoal; houses (over half the population of the
United States live in wooden houses); the wooden parts of masonry and
steel buildings; scaffolding; barns, sheds and outhouses; ships, with
all their parts, and the masts and trim of steel ships, boats
and canoes; oars and paddles; railway ties (annual expenditure
$50,000,000), railway cars, a million in number; trestles and bridges
(more than 2,000 miles in length); posts and fencing; cooperage
stock (low estimate, $25,000,000 annually); packing crates, including
coffins; baskets; electric wire poles (annual cost about $10,000,000);
piles and submerged structures, like canal locks and water-wheels;
windmills; mining timbers (yearly cost, $7,500,000), indispensable
in all mining operations (for every 100 tons of coal mined, 2 tons of
mining timber are needed); street paving; veneers ($5,000,000.00 worth
made annually); vehicles, including carriages, wagons, automobiles
and sleighs; furniture; machines and their parts; patterns for metal
molding; tools and tool handles; musical instruments; cigar boxes;
matches; toothpicks; pencils; (315 million a year in the U. S.,
requiring over 7 million cubic feet of wood); engraving blocks;
shoe lasts, shoe trees and parts of shoes; hat blocks; agricultural
implements; hop and bean poles; playthings and toys, for both children
and adults; Christmas trees and decorations; pipes; walking sticks;
umbrella handles; crutches and artificial limbs; household utensils;
excelsior.
Products other than wood: Turpentine and resin (worth $20,000,000 a
year); tar; oils; tan-bark, 1-1/2 million cords (worth $13,000,000
a year); wood alcohol; wood pulp (worth $15,000,000 a year); nuts;
cellulose for collars, combs and car wheels; balsam, medicines;
lampblack; dyes; paper fiber (xylolin) for textiles; shellac and
varnish ($8,500,000 worth imported in 1907); vinegar and acetic acid;
confections (including maple sugar and syrup at $2,500,000 a year).
(3) The _Esthetic_ and sentimental uses of the forest, tho not to
be estimated in dollars and cents, are nevertheless of incalculable
benefit to the community. They would include the use of the forest
as pleasure grounds, for hunting, fishing, camping, photography, and
general sightseeing. Notable instances of the growing appreciation of
these uses of the forest are the reservation of the Yellowstone and
Yosemite Parks as pleasure grounds.
PRESERVATION.
The second object of forestry is the preservation of the forest, or
continued reproduction.
In addition to obtaining crops of trees, the forester plans to keep
the forest in such condition that it will constantly reproduce itself
and never become exhausted.
This does not mean that no forests are to be cut down, or that a given
area, once a forest, is to be always a forest. Just as the individual
farmer needs some land for fields, some for pasture, and some for
woodlots, so the nation needs some for cities, some for farms, some
for pleasure grounds, and some for forests. But it does mean that
fruitful forests shall not be turned into wildernesses as thousands of
square miles now are, by the methods of destructive lumbering.
In general, better land is necessary for agriculture than for
forestry, and it is therefore only the part of wisdom to use the
better land for fields and reserve the poorer land for forests. There
are in the United States enormous regions that are fit for nothing but
forests, but many of these, as in Wisconsin, Minnesota, and Michigan,
have simply been denuded of their trees and no provision has been made
for their reproduction. This then is the second aim of forestry,--to
treat the forest so that it will continue to reproduce itself.
In order to obtain this result, certain forest conditions have to be
preserved. What these conditions are, we have already noticed (see
Chap. V, The Forest Organism). They are partly topographical and
climatic and partly historical. They include such factors as, soil,
moisture, temperature, and light, the forest cover, the forest floor,
the density and mixture of growth, all conditions of forest growth.
It is only as the forester preserves these conditions, or to put it
otherwise, it is only as he obeys the laws of the forest organism that
he can preserve the forest. For a long period of our national history,
we Americans were compelled to conform our life and institutions to
the presence of the primeval forest, but by long observation of what
happens naturally in the forest, there have been developed in Europe
and in America certain ways of handling it so as to make it our
servant and not our master.
These ways are called silvicultural systems. They are all based on the
nature of the forest itself, and they succeed only because they are
modifications of what takes place naturally in the woods.
As we have seen above (p. 220) trees reproduce themselves either by
sprouts or by seeds. This fact gives rise to two general methods of
reproduction, called the coppice systems and the seed systems.
[Illustration: Fig. 123. Chestnut Coppice. _U. S. Forest Service._]
_Coppice_, Fig. 123. In the simpler form of this system, the forest
is divided into a certain number of parts, say thirty, and one part is
cut down each year. New sprouts at once start up, which will mature
a year later than those in the part cut the previous year. Where the
trees of each part are thirty years old at cutting, thirty years is
called the "rotation period." The coppice is said to be managed on
a thirty-year rotation. The system is widely used in eastern United
States, for fuel, posts, charcoal, railway ties, and other small
stuff, as well as for tan-bark. This system is modified by maintaining
an overwood composed of seedling trees or selected sprouts above a
stand of sprouts. This is called the Reserve Sprout method and is used
with admirable results by the French.
_Seed Forests._ In contrast with coppice forests, those raised from
seeds produce the best class of timber, such as is used for saw logs.
[Illustration: Fig. 124. Seeding from the Side. White Pine. New
Hampshire. _U. S. Forest Service._]
_Seeding from the side_, Fig. 124. Many forests naturally spread at
their borders from the scattering of their seeds. "Old field pine" is
so called from its tendency to spread in this way on old fields. This
natural "Seeding from the Side" has given rise to the "Group System,"
in which an area of ripe trees is cut off and the trees alongside are
depended upon to reproduce new ones on the cut-over area. The openings
are gradually enlarged until all the old timber is cut out, and the
young growth has taken its place. In its best form there is a definite
"rotation period," say eighty years. This system is simple, safe, and
very useful, especially for small openings in woodlots. A modification
of this is the "Strip System," in which long narrow openings, say
seventy-five yards wide, are cut out and gradually widened. The strips
are cut in the proper direction so that the prevailing winds will
cross them, both for the sake of avoiding windfalls and to help
scatter the seed. Where the soil is very dry, the strips may run east
and west to protect the seedlings from the sun.
[Illustration: Fig. 125. Virgin Forest, Trees of All Ages. Jackson
Co., North Carolina. _U.S. Forest Service._]
_Selection Forests._ The typical virgin forest, Fig. 125, is one in
which trees of all ages are closely intermingled, and it may be either
"mixed" or "pure." If a farmer had a woodlot of this character and
every year went over it with the ax, cutting out such trees as he
needed for his purpose, and also trees whose removal would improve the
woods, but taking care not to cut out each year more than the amount
of the average growth, he would be using the "Selection System." This
system is the best way of keeping a forest dense and of preserving
one which is difficult to start afresh, as on a mountain slope; it is
practicable where the woods are small or under a high state of care,
as in Europe, where this system has been in use for seven centuries.
But the cost of road maintenance and of logging is high and it is
therefore impracticable in most lumber regions in the United States,
except for woods of especial value, like black walnut.
_Localized Selection._ If instead of the whole forest being treated in
this way every year, it were divided up into perhaps twenty parts, and
from each part there were taken out each year as much lumber as would
equal the annual growth of the whole forest, such a system would be
called "Localized Selection." The cost of logging would be greatly
reduced and if care were taken to leave standing some seed trees and
to cut no trees below a determined size, as twelve inches, the forest
would maintain itself in good condition. This system has been applied
with great success in certain private forests in the Adirondacks.
_Regular Seed Forest or High Forest._ In the system already mentioned
above of seeding from the side, the trees near the cut areas are
depended upon to seed these areas. Moreover, no especial pains are
taken to preserve the forest floor and the forest cover. But all trees
do not bear seeds annually, nor do their seedlings thrive under such
conditions. In other words, in some forests especial pains must
be taken to secure reproduction, and the forest conditions must
be maintained with special reference to the growing crop. For this
purpose, the cuttings take place thru a series of years, sometimes
lasting even twenty years. These reproduction cuttings have reference,
now to a stimulus to the seed trees, now to the preparation of the
seed bed, now to the encouragement of the seedlings. Then later,
the old crop is gradually cut away. Later still, in twenty or thirty
years, the new forest is thinned, and when it reaches maturity,
perhaps in one hundred or two hundred years, the process is repeated.
This is called the "Regular Seed Forest." It produces very valuable
timber, and has been used for a long time in Switzerland, especially
for beech and balsam.
The system is complicated and therefore unsafe in ignorant hands, and
the logging is expensive.
_Two-storied Seed Forest._ A modification of the system of Regular
Seed Forest is the planting of another and a tolerant species of tree
under older intolerant trees to make a cover for the soil, to prevent
the growth of grass and weeds, and to improve the quality of the upper
growth.[2]
An illustration of a natural two-storied seed forest is shown in Fig.
126.
[Illustration: No. 126. Two-storied Seed Forest. Fir under Beech,
Germany. _U. S. Forest Service._]
_Planting._ The planting of forest trees is a comparatively
unimportant part of modern forestry. It is a mistaken idea, not
uncommon, that the usual way of reproducing forests is to plant trees.
It is true that in the pineries of North Germany and in the spruce
forests of Saxony, it is common to cut clean and then replant, but it
is absurd to conclude, as some have done, that forestry consists of
planting a tree every time one is cut. Even if planting were the best
method, many more than one tree would have to be planted for each one
cut, in order to maintain the forest. So far as America is concerned,
not for a long time will planting be much used for reproduction.
The greater portion of American woodlands is in the
condition of culled forests, that is, forests from which
the merchantable trees have been cut, leaving the younger
individuals, as well as all trees belonging to unmarketable
species. Even on the areas where the lumbermen have made a
clean cut of the original timber, new trees will come up of
themselves from seeds blown from the surrounding forests or
falling from occasional individuals left standing. (Bruncken,
p. 133.)
The usefulness of planting in America is mainly for reclaiming
treeless regions, as in the west, and where timber is high priced.
The area of planted timber in the Middle West aggregates many hundred
thousand acres, once waste land, now converted into useful woods.[3]
Planting has been made possible in the far west by extensive
irrigation systems, and farther east by the lessening of prairie
fires, which once set the limit to tree growth in the prairie states.
In many parts of Illinois, southern Wisconsin and other prairie
States, there is much more forest land than there was twenty-five
years ago.
What planting can do, may be seen on some worn out pastures in New
England, Fig. 127. With the western movement of agriculture,
the abandoned farms of New England are to some extent becoming
re-forested, both naturally and by planting, as with white pine, which
grows even on sandy soil. Between 1820 and 1880, there was a period of
enthusiastic white-pine planting in New England, and tho the interest
died on account of the cheap transportation of western lumber, those
early plantations prove that white pine can be planted at a profit
even on sand barrens. Once worn out and useless pastures are now worth
$150 an acre and produce yearly a net income of $3 or more an acre.
[Illustration: Fig. 127. Planted White Pine, Fifty Years Old,
Bridgewater, Mass. _U. S. Forest Service._]
IMPROVEMENT.
Besides utilization and preservation, the third main object of
forestry is the improvement of the forest. It is not an uncommon
mistake to suppose that the virgin forest is the best forest for human
purposes. It is a comparatively new idea, especially in America, that
a forest can be improved; that is, that better trees can be raised
than those which grow naturally. Lumbermen commonly say, "You never
can raise a second growth of white pine as good as the first growth."
As if this "first growth" were not itself the successsor of thousands
of other generations! There is even a legend that white pine will not
grow in its old habitat. Says Bruncken,
Many people probably imagine that a primeval wood, "by
nature's own hand planted," cannot be surpassed in the number
and size of its trees, and consequently in the amount of wood
to be derived from it. But the very opposite is true. No wild
forest can ever equal a cultivated one in productiveness. To
hope that it will, is very much as if a farmer were to expect
a full harvest from the grain that may spring up spontaneously
in his fields without his sowing. A tract of wild forest in
the first place does not contain so many trees as might grow
thereon, but only so many as may have survived the struggle
for life with their own and other species of plants occupying
the locality. Many of the trees so surviving never attain
their best development, being suppressed, overshadowed, and
hindered by stronger neighbors. Finally much of the space that
might be occupied by valuable timber may be given up to trees
having little or no market value. The rule is universal that
the amount and value of material that can be taken from an
area of wild forest remains far behind what the same land
may bear if properly treated by the forester. It is certain,
therefore, that in the future, when most American forests
shall be in a high state of cultivation, the annual output of
forests will, from a much restricted area, exceed everything
known at the present day. (Bruncken, _North American Forests
and Forestry_, pp. 134-135.)
It is probable that the virgin forest produces but a tithe of
the useful material which it is capable of producing. (Fernow,
p. 98.)
Mr. Burbank has demonstrated that trees can be bred for any
particular quality,--for largeness, strength, shape, amount of
pitch, tannin, sugar and the like, and for rapidity of
growth; in fact that any desirable attribute of a tree may
be developed simply by breeding and selecting. He has created
walnut trees, by crossing common varieties, that have grown
six times as much in thirteen years as their ancestors did in
twenty-eight years, preserving at the same time, the strength,
hardness and texture of their forebears. The grain of the wood
has been made more beautiful at the same time. The trees are
fine for fuel and splendidly adapted to furniture manufacture.
(Harwood, _The New Earth_, p. 179.)
Nature provides in the forest merely those varieties that will
survive. Man, by interfering in Nature's processes but obeying her
laws, raises what he wants. Nature says: those trees that survive
are fit and does not care whether the trees be straight or crooked,
branched or clear. Man says: those trees shall survive which are fit
for human uses. Man raises better grains and fruits and vegetables
than Nature, unaided, can, and, in Europe, better trees for lumber. In
America there has been such an abundance of trees good enough for our
purposes that we have simply gone out and gathered them, just as a
savage goes out to gather berries and nuts. Some day our descendants
will smile at our treatment of forests much as we smile at
root-digging savages, unless, indeed, we so far destroy the forests
that they will be more angered than amused. In Europe and Japan, the
original supply of trees having been exhausted, forests have been
cultivated for centuries with the purpose of raising crops larger in
quantity and better in quality.
There are various methods used in forest improvement. Improvement
cuttings, as the name implies, are cuttings made to improve the
quality of the forest, whether by thinning out poor species of trees,
unsound trees, trees crowding more valuable ones, or trees called
"wolves"; that is, trees unduly overshadowing others. Improvement
cuttings are often necessary as a preliminary step before any
silvicultural system can be applied. Indeed, many of the silvicultural
systems involve steady improvement of the forest.
The pruning of branches is a method of improvement, carrying on the
natural method by which trees in a forest clean themselves of their
branches.
Seeds of valuable species are often sowed, when the conditions are
proper, in order to introduce a valuable species, just as brooks
and ponds are stocked with fine fish. In general it may be said that
improvement methods are only in their infancy, especially in America.
[Footnote 1: A concise and interesting statement of the
relation of the forest to rain and floods is to be found in
Pinchot: _Primer of Forestry_, Bulletin No. 24, Part II, Chap.
III.]
[Footnote 2: For an interesting account of an application of
this method, see Ward, p. 35.]
[Footnote 3: To encourage such forest extension, the Forest
Service is doing much by the publication of bulletins
recommending methods and trees suited to special regions, as,
e.g., on Forest Planting in Illinois, in the Sand Hill Region
of Nebraska, on Coal Lands in Western Pennsylvania, in Western
Kansas, in Oklahoma and adjacent regions, etc.]
THE USE OF THE FOREST.
REFERENCES:[A]
I Utilization.
Pinchot, _Primer_, II, pp. 14-18, 38-48.
Bruncken, pp. 121-131, _For. Bull._ No. 61.
(1) Protective.
Pinchot, _Primer_, II, pp. 66-73.
Craft, _Agric. Yr. Bk._, 1905, pp. 636-641, (Map. p. 639.)
Toumey, _Agric. Yr. Bk._, 1903, p. 279.
Bruncken, pp. 166-173.
_For. and Irrig._, passim.
Shaler, I, pp. 485-489.
(2) Productive.
Kellogg, _For. Bull._, No. 74,
Fernow, _For. Invest._, p. 9.
Roth, _First Book_, p. 133.
Zon & Clark, _Agric. Yr. Bk._, 1907, p. 277.
Boulger, pp. 60-76.
Roth, _Agric. Yr. Bk._, 1896, p. 391.
Fernow, _Economics_, pp. 23-33.
(3) Esthetic.
Roth, _First Book_, p. 180.
II Preservation.
Pinchot, _Primer_, II, pp. 18-36.
Bruncken, pp. 95, 190.
Graves, _For. Bull._, No. 26, pp. 67-70.
Roth, _First Book_, pp. 41-76, 193-194.
Roth, _For. Bull._, No. 16, pp. 8, 9.
Fernow, _Economics_, 165-196.
Planting.
Roth, _First Book_, pp. 76-94, 195-198.
Hall, _Agric. Yr. Bk._, 1902, pp. 145-156.
_For. Circs._, Nos. 37, 41, 45, 81.
Bruncken, pp. 92, 133.
_Forestry Bulletins_ Nos. 18, 45, 52, 65.
III Improvement.
Bruncken, pp. 134-135, 152-160.
Graves, _For. Bull._, No. 26, p. 39.
Pinchot, _Adirondack Spruce_, p. 4.
Harwood, pp. 143-181.
[Footnote A: For general bibliography, see p. 4.]
APPENDIX.
HOW TO DISTINGUISH THE DIFFERENT KINDS OF WOOD.[A]
BY B. E. FERNOW AND FILIBERT ROTH.
The carpenter or other artisan who handles different woods, becomes
familiar with those he employs frequently, and learns to distinguish
them thru this familiarity, without usually being able to state the
points of distinction. If a wood comes before him with which he is not
familiar, he has, of course, no means of determining what it is, and
it is possible to select pieces even of those with which he is well
acquainted, different in appearance from the general run, that will
make him doubtful as to their identification. Furthermore, he may
distinguish between hard and soft pines, between oak and ash, or
between maple and birch, which are characteristically different; but
when it comes to distinguishing between the several species of pine or
oak or ash or birch, the absence of readily recognizable characters is
such that but few practitioners can be relied upon to do it. Hence, in
the market we find many species mixed and sold indiscriminately.
To identify the different woods it is necessary to have a knowledge of
the definite, invariable differences in their structure, besides
that of the often variable differences in their appearance. These
structural differences may either be readily visible to the naked eye
or with a magnifier, or they may require a microscopical examination.
In some cases such an examination can not be dispensed with, if we
would make absolutely sure. There are instances, as in the pines,
where even our knowledge of the minute anatomical structure is not yet
sufficient to make a sure identification.
In the following key an attempt has been made--the first, so far as
we know, in English literature--to give a synoptical view of the
distinctive features of the commoner woods of the United States, which
are found in the markets or are used in the arts. It will be observed
that the distinction has been carried in most instances no further
than to genera or classes of woods, since the distinction of species
can hardly be accomplished without elaborate microscopic study, and
also that, as far as possible, reliance has been placed only on such
characteristics as can be distinguished with the naked eye or a simple
magnifying glass, in order to make the key useful to the largest
number. Recourse has also been taken for the same reason to the less
reliable and more variable general external appearance, color, taste,
smell, weight, etc.
The user of the key must, however, realize that external appearance,
such, for example, as color, is not only very variable but also very
difficult to describe, individual observers differing especially in
seeing and describing shades of color. The same is true of statements
of size, when relative, and not accurately measured, while weight and
hardness can perhaps be more readily approximated. Whether any feature
is distinctly or only indistinctly seen will also depend somewhat
on individual eyesight, opinion, or practice. In some cases the
resemblance of different species is so close that only one other
expedient will make distinction possible, namely, a knowledge of the
region from which the wood has come. We know, for instance, that no
longleaf pine grows in Arkansas and that no white pine can come from
Alabama, and we can separate the white cedar, giant arbor vitae of the
West and the arbor vitae of the Northeast, only by the difference of
the locality from which the specimen comes. With all these limitations
properly appreciated, the key will be found helpful toward greater
familiarity with the woods which are more commonly met with.
The features which have been utilized in the key and with which--their
names as well as their appearance--therefore, the reader must
familiarize himself before attempting to use the key, are mostly
described as they appear in cross-section. They are:
(1) Sap-wood and heart-wood (see p. 17), the former being the wood
from the outer and the latter from the inner part of the tree. In some
cases they differ only in shade, and in others in kind of color, the
heart-wood exhibiting either a darker shade or a pronounced color.
Since one can not always have the two together, or be certain whether
he has sap-wood or heart-wood, reliance upon this feature is, to
be sure, unsatisfactory, yet sometimes it is the only general
characteristic that can be relied upon. If further assurance is
desired, microscopic structure must be examined; in such cases
reference has been made to the presence or absence of tracheids in
pith rays and the structure of their walls, especially projections and
spirals.
(2) Annual rings, their formation having been described on page 19.
(See also Figs. 128-130.) They are more or less distinctly marked,
and by such marking a classification of three great groups of wood is
possible.
(3) Spring wood and summer wood, the former being the interior (first
formed wood of the year), the latter the exterior (last formed) part
of the ring. The proportion of each and the manner in which the one
merges into the other are sometimes used, but more frequently the
manner in which the pores appear distributed in either.
(4) Pores, which are vessels cut thru, appearing as holes in
cross-section, in longitudinal section as channels, scratches, or
identifications. (See p. 23 and Figs. 129 and 130.) They appear
only in the broad-leaved, so called, hard woods; their relative size
(large, medium, small, minute, and indistinct when they cease to be
visible individually by the naked eye) and manner of distribution in
the ring being of much importance, and especially in the summer
wood, where they appear singly, in groups, or short broken lines, in
continuous concentric, often wavy lines, or in radial branching lines.
(5) Resin ducts (see p. 26 and Fig. 128) which appear very much like
pores in cross-section, namely, as holes or lighter or darker colored
dots, but much more scattered. They occur only in coniferous woods,
and their presence or absence, size, number, and distribution are an
important distinction in these woods.
(6) Pith rays (see p. 21 and Figs. 129 and 130), which in
cross-section appear as radial lines, and in radial section as
interrupted bands of varying breadth, impart a peculiar luster to that
section in some woods. They are most readily visible with the naked
eye or with a magnifier in the broad-leaved woods. In coniferous
woods they are usually so fine and closely packed that to the casual
observer they do not appear. Their breadth and their greater or less
distinctness are used as distinguishing marks, being styled fine,
broad, distinct, very distinct, conspicuous, and indistinct when no
longer visible by the naked (strong) eye.
(7) Concentric lines, appearing in the summer wood of certain species
more or less distinct, resembling distantly the lines of pores but
much finer and not consisting of pores. (See Fig. 129.)
Of microscopic features, the following only have been referred to:
(8) Tracheids, a description of which is to be found on page 28.
(9) Pits, simple and bordered, especially the number of simple pits
in the cells of the pith rays, which lead into each of the adjoining
tracheids.
For standards of weight, consult table on pages 50 and 192; for
standards of hardness, table on page 195.
Unless otherwise stated the color refers always to the fresh
cross-section of a piece of dry wood; sometimes distinct kinds of
color, sometimes only shades, and often only general color effects
appear.
[Footnote A: From Forestry Bulletin No. 10, _U. S. Department
of Agriculture_.]
HOW TO USE THE KEY.
Nobody need expect to be able to use successfully any key for the
distinction of woods or of any other class of natural objects without
some practice. This is especially true with regard to woods, which
are apt to vary much, and when the key is based on such meager general
data as the present. The best course to adopt is to supply one's self
with a small sample collection of woods, accurately named. Small,
polished tablets are of little use for this purpose. The pieces
should be large enough, if possible, to include pith and bark, and of
sufficient width to permit ready inspection of the cross-section.
By examining these with the aid of the key, beginning with the
better-known woods, one will soon learn to see the features described
and to form an idea of the relative standards which the maker of the
key had in mind. To aid in this, the accompanying illustrations will
be of advantage. When the reader becomes familiar with the key, the
work of identifying any given piece will be comparatively easy. The
material to be examined must, of course, be suitably prepared. It
should be moistened; all cuts should be made with a very sharp knife
or razor and be clean and smooth, for a bruised surface reveals but
little structure. The most useful cut may be made along one of the
edges. Instructive, thin, small sections may be made with a sharp
penknife or razor, and when placed on a piece of thin glass, moistened
and covered with another piece of glass, they may be examined by
holding them toward the light.
Finding, on examination with the magnifier, that it contains pores, we
know it is not coniferous or non-porous. Finding no pores collected
in the spring-wood portion of the annual ring, but all scattered
(diffused) thru the ring, we turn at once to the class of
"Diffuse-porous woods." We now note the size and manner in which
the pores are distributed thru the ring. Finding them very small and
neither conspicuously grouped, nor larger nor more abundant in the
spring-wood, we turn to the third group of this class. We now note
the pith rays, and finding them neither broad nor conspicuous, but
difficult to distinguish, even with the magnifier, we at once exclude
the wood from the first two sections of this group and place it in the
third, which is represented by only one kind, cottonwood. Finding the
wood very soft, white, and on the longitudinal section with a silky
luster, we are further assured that our determination is correct.
We may now turn to the list of woods and obtain further information
regarding the occurrence, qualities, and uses of the wood.
Sometimes our progress is not so easy; we may waver in what group or
section to place the wood before us. In such cases we may try each
of the doubtful roads until we reach a point where we find ourselves
entirely wrong and then return and take up another line; or we may
anticipate some of the later mentioned features and finding them apply
to our specimen, gain additional assurance of the direction we ought
to travel. Color will often help us to arrive at a speedy decision.
In many cases, especially with conifers, which are rather difficult to
distinguish, a knowledge of the locality from which the specimen comes
is at once decisive. Thus, northern white cedar, and bald cypress, and
the cedar of the Pacific will be identified, even without the somewhat
indefinite criteria given in the key.
KEY TO THE MORE IMPORTANT WOODS OF NORTH AMERICA.
I. NON-POROUS WOODS--Pores not visible or conspicuous on
cross-section, even with magnifier. Annual rings distinct by denser
(dark colored) bands of summer wood (Fig. 128).
[Illustration: Fig. 128. "Non-porous" Woods. _A_, fir; _B_, "hard"
pine; _C_, soft pine; _ar_, annual ring; _o.e._, outer edge of ring;
_i.e._, inner edge of ring; _s.w._, summer wood; _sp.w._, spring wood;
_rd._, resin ducts.]
II. RING-POROUS WOODS--Pores numerous, usually visible on
cross-section without magnifier. Annual rings distinct by a zone of
large pores collected in the spring wood, alternating with the denser
summer wood (Fig. 129).
[Illustration: Fig. 129. "Ring-porous" Woods White Oak and Hickory.
_a. r._, annual ring; _su. w._, summer wood; _sp. w._, spring wood;
_v_, vessels or pores; _c. l._, "concentric" lines; _rt_, darker
tracts of hard fibers forming the firm part of oak wood; _pr_, pith
rays.]
III. DIFFUSE-POROUS WOODS--Pores numerous, usually not plainly visible
on cross-section without magnifier. Annual rings distinct by a fine
line of denser summer wood cells, often quite indistinct; pores
scattered thru annual ring, no zone of collected pores in spring wood
(Fig. 130).
[Illustration: Fig. 130. "Diffuse-porous" Woods. _ar_, annual ring;
_pr_, pith rays which are "broad" at _a_, "fine" at _b_, "indistinct"
at _d_.]
NOTE.--The above described three groups are exogenous, i.e., they
grow by adding annually wood on their circumference. A fourth group
is formed by the endogenous woods, like yuccas and palms, which do not
grow by such additions.
I.--NON-POROUS WOODS.
(Includes all coniferous woods.)
A. Resin ducts wanting.[1]
1. No distinct heart-wood.
_a._ Color effect yellowish white; summer wood darker yellowish
(under microscope pith ray without tracheids)..........FIRS.
_b._ Color effect reddish (roseate) (under microscope pith
ray with tracheids) ................................HEMLOCK.
2. Heart-wood present, color decidedly different in kind from
sap-wood.
_a._ Heart-wood light orange red; sap-wood, pale lemon; wood,
heavy and hard .........................................YEW.
_b._ Heartwood purplish to brownish red; sap-wood yellowish
white; wood soft to medium hard, light, usually with
aromatic odor, ...................................RED CEDAR.
_c._ Heart-wood maroon to terra cotta or deep brownish red;
sap-wood light orange to dark amber, very soft and light,
no odor; pith rays very distinct, specially pronounced
on radial section ..................................REDWOOD.
3. Heart-wood present, color only different in shade from sap-wood,
dingy-yellowish brown.
_a._ Odorless and tasteless ........................BALD CYPRESS.
_b._ Wood with mild resinous odor, but tasteless ....WHITE CEDAR.
_c._ Wood with strong resinous odor and peppery taste when
freshly cut, ................................INCENSE CEDAR.
B. Resin ducts present.
1. No distinct heartwood; color white, resin ducts very small,
not numerous ............................................SPRUCE.
2. Distinct heart-wood present.
_a._ Resin ducts numerous, evenly scattered thru the ring.
_a.'_ Transition from spring wood to summer wood gradual;
annual ring distinguished by a fine line of dense
summer-wood cells; color, white to yellowish red;
wood soft and light .......................SOFT PINES.[2]
_b.'_ Transition from spring wood to summer wood more or
less abrupt; broad bands of dark-colored summer
wood; color from light to deep orange; wood medium
hard and heavy ............................HARD PINES.[2]
_b._ Resin ducts not numerous nor evenly distributed.
_a'._ Color of heart-wood orange-reddish, sap-wood yellowish
(same as hard pine); resin ducts frequently combined in
groups of 8 to 30, forming lines on the cross-section
(tracheids with spirals), ..............DOUGLAS SPRUCE.
_b'._ Color of heart-wood light russet brown; of sap-wood
yellowish brown; resin ducts very few, irregularly
scattered (tracheids without spirals) ........TAMARACK.
[Footnote 1: Soft and hard pines are arbitrary distinctions
and the two not distinguishable at the limit.]
[Footnote 2: To discover the resin ducts a very smooth surface
is necessary, since resin ducts are frequently seen only with
difficulty, appearing on the cross-section as fine whiter
or darker spots normally scattered singly, rarely in groups,
usually in the summer wood of the annual ring. They are
often much more easily seen on radial, and still more so on
tangential sections, appearing there as fine lines or dots of
open structure of different color or as indentations or pin
scratches in a longitudinal direction.]
====
ADDITIONAL NOTES FOR DISTINCTIONS IN THE GROUP.
Spruce is hardly distinguishable from fir, except by the existence of
the resin ducts, and microscopically by the presence of tracheids
in the medullary rays. Spruce may also be confounded with soft pine,
except for the heart-wood color of the latter and the larger, more
frequent, and more readily visible resin ducts.
In the lumber yard, hemlock is usually recognized by color and the
silvery character of its surface. Western hemlocks partake of this
last character to a less degree.
Microscopically the white pine can be distinguished by having usually
only one large pit, while spruce shows three to five very small
pits in the parenchyma cells of the pith ray communicating with the
tracheid.
The distinction of the pines is possible only by microscopic
examination. The following distinctive features may assist in
recognizing, when in the log or lumber pile, those usually found in
the market:
The light, straw color, combined with great lightness and softness,
distinguishes the white pines (white pine and sugar pine) from the
hard pines (all others in the market), which may also be recognized
by the gradual change of spring wood into summer wood. This change
in hard pines is abrupt, making the summer wood appear as a sharply
defined and more or less broad band.
The Norway pine, which may be confounded with the shortleaf pine, can
be distinguished by being much lighter and softer. It may also,
but more rarely, be confounded with heavier white pine, but for the
sharper definition of the annual ring, weight, and hardness.
The longleaf pine is strikingly heavy, hard, and resinous, and usually
very regular and narrow ringed, showing little sap-wood, and differing
in this respect from the shortleaf pine and loblolly pine, which
usually have wider rings and more sap-wood, the latter excelling in
that respect.
The following convenient and useful classification of pines into four
groups, proposed by Dr. H. Mayr, is based on the appearance of the
pith ray as seen in a radial section of the spring wood of any ring:
Section I. Walls of the tracheids of the pith ray with dentate
projections.
_a._ One to two large, simple pits to each tracheid on the radial
walls of the cells of the pith ray.--Group 1. Represented in
this country only by _P. resinosa_.
_b._ Three to six simple pits to each tracheid, on the walls of
the cells of the pith ray.--Group 2. _P. taeda_, _palustris_,
etc., including most of our "hard" and "yellow" pines.
Section II. Walls of tracheids of pith ray smooth, without dentate
projections.
_a._ One or two large pits to each tracheid on the radial walls of
each cell of the pith ray.--Group 3. _P. strobus, lambertiana_,
and other true white pines.
_b._ Three to six small pits on the radial walls of each cell of
the pith ray. Group 4. _P. parryana_, and other nut pines,
including also _P. balfouriana_.
====
II.--RING-POROUS WOODS.
(Some of Group D and cedar elm imperfectly ring-porous.)
A. Pores in the summer wood minute, scattered singly or in groups, or in
short broken lines, the course of which is never radial.
1. Pith rays minute, scarcely distinct.
_a._ Wood heavy and hard; pores in the summer wood not in clusters.
_a.'_ Color of radial section not yellow.................ASH.
_b.'_ Color of radial section light yellow; by which,
together with its hardness and weight, this
species is easily recognized, ............OSAGE ORANGE.
_b._ Wood light and soft; pores in the summer wood in clusters
of 10 to 30 .......................................CATALPA.
2. Pith rays very fine, yet distinct; pores in summer wood
usually single or in short lines; color of heart-wood
reddish brown; of sap-wood yellowish white; peculiar odor
on fresh section .....................................SASSAFRAS.
3. Pith rays fine, but distinct.
_a._ Very heavy and hard; heart-wood yellowish brown.
BLACK LOCUST.
_b._ Heavy; medium hard to hard.
_a.'_ Pores in summer wood very minute, usually in small
clusters of 3 to 8; heart-wood light orange brown.
RED MULBERRY.
_b.'_ Pores in summer wood small to minute, usually
isolated; heart-wood cherry red ..........COFFEE TREE.
4. Pith rays fine but very conspicuous, even without magnifier.
Color of heart-wood red; of sap-wood pale lemon ...HONEY LOCUST.
B. Pores of summer wood minute or small, in concentric wavy and
sometimes branching lines, appearing as finely-feathered hatchings
on tangential section.
1. Pith rays fine, but very distinct; color greenish white.
Heart-wood absent or imperfectly developed ...........HACKBERRY.
2. Pith rays indistinct; color of heart-wood reddish brown;
sap-wood grayish to reddish white .........................ELMS.
C. Pores of summer wood arranged in radial branching lines (when very
crowded radial arrangement somewhat obscured).
1. Pith rays very minute, hardly visible .................CHESTNUT.
2. Pith rays very broad and conspicuous .......................OAK.
D. Pores of summer wood mostly but little smaller than those of the
spring wood, isolated and scattered; very heavy and hard woods.
The pores of the spring wood sometimes form but an imperfect zone.
(Some diffuse-porous woods of groups A and B may seem to belong
here.)
1. Fine concentric lines (not of pores) as distinct, or nearly so,
as the very fine pith rays; outer summer wood with a tinge of
red; heart-wood light reddish brown ....................HICKORY.
2. Fine concentric lines, much finer than the pith rays; no
reddish tinge in summer wood; sap-wood white; heart-wood
blackish .............................................PERSIMMON.
====
ADDITIONAL NOTES FOR DISTINCTIONS IN THE GROUP.
Sassafras and mulberry may be confounded but for the greater weight
and hardness and the absence of odor in the mulberry; the radial
section of mulberry also shows the pith rays conspicuously.
Honey locust, coffee tree, and black locust are also very similar in
appearance. The honey locust stands out by the conspicuousness of the
pith rays, especially on radial sections, on account of their height,
while the black locust is distinguished by the extremely great weight
and hardness, together with its darker brown color.
[Illustration: Fig. 131. Wood of Coffee Tree.]
The ashes, elms, hickories, and oaks may, on casual observation,
appear to resemble one another on account of the pronounced zone of
porous spring wood. (Figs. 129, 132, 135.) The sharply defined large
pith rays of the oak exclude these at once; the wavy lines of pores in
the summer wood, appearing as conspicuous finely-feathered hatchings
on tangential section, distinguish the elms; while the ashes differ
from the hickory by the very conspicuously defined zone of spring wood
pores, which in hickory appear more or less interrupted. The reddish
hue of the hickory and the more or less brown hue of the ash may also
aid in ready recognition. The smooth, radial surface of split hickory
will readily separate it from the rest.
[Illustration: Fig. 132. _A_, black ash; _B_, white ash; _C_, green
ash.]
The different species of ash may be identified as follows (Fig. 132):
1. Pores in the summer wood more or less united into lines.
_a._ The lines short and broken, occurring mostly near the limit
of the ring .......................................WHITE ASH.
_b._ The lines quite long and conspicuous in most parts of the
summer wood .......................................GREEN ASH.
2. Pores in the summer wood not united into lines, or rarely so.
_a._ Heart-wood reddish brown and very firm ..............RED ASH.
_b._ Heart-wood grayish brown, and much more porous ....BLACK ASH.
In the oaks, two groups can be readily distinguished by the manner in
which the pores are distributed in the summer wood. (Fig. 133.) In
the white oaks the pores are very fine and numerous and crowded in
the outer part of the summer wood, while in the black or red oaks the
pores are larger, few in number, and mostly isolated. The live oaks,
as far as structure is concerned, belong to the black oaks, but are
much less porous, and are exceedingly heavy and hard.
[Illustration: Fig. 133. Wood of Red Oak. (For white oak see fig. 129,
p. 291.)]
[Illustration: Fig. 134. Wood of Chestnut.]
[Illustration: Fig. 135. Wood of Hickory.]
====
III.--DIFFUSE-POROUS WOODS.
(A few indistinctly ring-porous woods of Group II, D, and cedar elm
may seem to belong here.)
A. Pores varying in size from large to minute; largest in spring wood,
thereby giving sometimes the appearance of a ring-porous arrangement.
1. Heavy and hard; color of heart-wood (especially on longitudinal
section) chocolate brown ..........................BLACK WALNUT.
2. Light and soft; color of heart-wood light reddish brown
BUTTERNUT.
B. Pores all minute and indistinct; most numerous in spring wood,
giving rise to a lighter colored zone or line (especially on
longitudinal section), thereby appearing sometimes ring-porous;
wood hard, heart-wood vinous reddish; pith rays very fine, but very
distinct. (See also the sometimes indistinct ring-porous cedar elm,
and occasionally winged elm, which are readily distinguished by the
concentric wavy lines of pores in the summer wood) .........CHERRY.
C. Pores minute or indistinct, neither conspicuously larger nor more
numerous in the spring wood and evenly distributed.
1. Broad pith rays present.
_a._ All or most pith rays broad, numerous, and crowded,
especially on tangential sections, medium heavy and hard,
difficult to split. ................................SYCAMORE.
_b._ Only part of the pith rays broad.
_a.'_ Broad pith rays well defined, quite numerous;
wood reddish white to reddish ....................BEECH.
_b.'_ Broad pith rays not sharply defined, made up of many
small rays, not numerous. Stem furrowed, and therefore
the periphery of section, and with it the annual rings
sinuous, bending in and out, and the large pith rays
generally limited to the furrows or concave portions.
Wood white, not reddish .....................BLUE BEECH.
2. No broad pith rays present.
_a._ Pith rays small to very small, but quite distinct.
_a.'_ Wood hard.
_a."_ Color reddish white, with dark reddish tinge in
outer summer wood ...........................MAPLE.
_b."_ Color white, without reddish tinge ...........HOLLY.
_b.'_ Wood soft to very soft.
_a."_ Pores crowded, occupying nearly all the space between
pith rays.
_a.'"_ Color yellowish white, often with a greenish tinge
in heart-wood ........................TULIP POPLAR.
CUCUMBER TREE.
_b.'"_ Color of sap-wood grayish, of heart-wood light to
dark reddish brown ......................SWEET GUM.
_b."_ Pores not crowded, occupying not over one-third the
space between pith rays; heart-wood brownish white
to very light brown .........................BASSWOOD.
_b._ Pith rays scarcely distinct, yet if viewed with ordinary
magnifier, plainly visible.
_a.'_ Pores indistinct to the naked eye.
_a."_ Color uniform pale yellow; pith rays not
conspicuous even on the radial section .....BUCKEYE.
_b."_ Sap-wood yellowish gray, heart-wood grayish brown;
pith rays conspicuous on the radial section.
SOUR GUM.
_b.'_ Pores scarcely distinct, but mostly visible as grayish
specks on the cross-section; sap-wood whitish,
heart-wood reddish ..............................BIRCH.
D. Pith rays not visible or else indistinct, even if viewed with
magnifier.
1. Wood very soft, white, or in shades of brown, usually with a
silky luster .................................COTTONWOOD (POPLAR).
====
ADDITIONAL NOTES FOR DISTINCTIONS IN THE GROUP.
Cherry and birch are sometimes confounded, the high pith rays on the
cherry on radial sections readily distinguishes it; distinct pores
on birch and spring wood zone in cherry as well as the darker
vinous-brown color of the latter will prove helpful.
Two groups of birches can be readily distinguished, tho specific
distinction is not always possible.
1. Pith rays fairly distinct, the pores rather few and not more
abundant in the spring wood: wood heavy, usually darker,
CHERRY BIRCH and YELLOW BIRCH.
2. Pith rays barely distinct, pores more numerous and commonly
forming a more porous spring wood zone; wood of medium weight,
CANOE OR PAPER BIRCH.
[Illustration: Fig. 136. Wood of Beech, Sycamore and Birch.]
The species of maple may be distinguished as follows:
1. Most of the pith rays broader than the pores and very
conspicuous ........................................SUGAR MAPLE.
2. Pith rays not or rarely broader than the pores, fine but
conspicuous.
_a._ Wood heavy and hard, usually of darker reddish color and
commonly spotted on cross-section ...............RED MAPLE.
_b._ Wood of medium weight and hardness, usually light colored.
SILVER MAPLE.
[Illustration: Fig. 137. Wood of Maple.]
Red maple is not always safely distinguished from soft maple. In box
elder the pores are finer and more numerous than in soft maple. The
various species of elm may be distinguished as follows:
1. Pores of spring wood form a broad band of several rows; easy
splitting, dark brown heart ............................RED ELM.
2. Pores of spring wood usually in a single row, or nearly so.
_a._ Pores of spring wood large, conspicuously so
WHITE ELM.
_b._ Pores of spring wood small to minute.
_a.'_ Lines of pores in summer wood fine, not as wide as the
intermediate spaces, giving rise to very compact grain
ROCK ELM.
_b.'_ Lines of pores broad, commonly as wide as the
intermediate spaces .........................WINGED ELM.
_c._ Pores in spring wood indistinct, and therefore hardly a
ring-porous wood .................................CEDAR ELM.
[Illustration: