Lower bolt, 2, 3, 6, 7, _The Mechanical Properties of Wood Including a Discussion of the Factors Affecting the Mechanical Properties, and Methods of Timber Testing

etc. } and

Upper bolt, 1, 4, 5, 8, 9, } tested

All green sticks from these two bolts will be tested as if they

were from the same bolt and according to the plan previously

outlined for green material from single bolts. The tests on the

air-dried material will be the same as on the green except for

the difference of seasoning.

The material will be tested at as near 12 per cent moisture as

is practicable. The approximate weight of the air-dried

specimens at 12 per cent moisture will be determined by

measuring while green 20 per cent of the sticks to be air-dried

and assuming their dry gravity to be the same as that of the

specimens tested green. This 20 per cent will be weighed as

often as is necessary to determine the proper time of test.

_Methods of Test_

All tests will be made according to Circular 38 except in case

of conflict with the instructions given below:

_Static bending_: The tests will be on specimens 2" X 2" X 30"

on 28-inch span. Load will be applied at the centre.

In all tests the load-deflection curve will be carried to or

beyond the maximum load. In one-third of the tests the

load-deflection curve will be continued to 6-inch deflection, or

till the specimen fails to support a 200-pound load. Deflection

readings for equal increments of load will be taken until well

past the elastic limit, after which the scale beam will be kept

balanced and the load read for each 0.1-inch deflection. The

load and deflection at first failure, maximum load and points of

sudden change, will be shown on the curve sheet even if they do

not occur at one of the regular load or deflection increments.

_Impact bending_: The impact bending tests will be on specimens

of the same size as those used in static bending. The span will

be 28 inches.

The tests will be by increment drop. The first drop will be 1

inch and the increase will be by increments of 1 inch till a

height of 10 inches is reached, after which increments of 2

inches will be used until complete failure occurs or 6-inch

deflection is secured.

A 50-pound hammer will be used when with drops up to 68 inches

it is practically certain that it will produce complete failure

or 6-inch deflection in the case of all specimens of a species.

For all other species, a 100-pound hammer will be used.

In all cases drum records will be made until first failure. Also

the height of drop causing complete failure or 6-inch deflection

will be noted.

_Compression parallel to grain_: This test will be on specimens

2" X 2" X 8" in size. On 20 per cent of these tests

load-compression curves for a 6-inch centrally located gauge

length will be taken. Readings will be continued until the

elastic limit is well passed. The other 80 per cent of the tests

will be made for the purpose of obtaining the maximum load only.

_Compression perpendicular to grain_: This test will be on

specimens 2" X 2" X 6" in size. The bearing plates will be 2

inches wide. The rate of descent of the moving head will be

0.024 inch per minute. The load-compression curve will be

plotted to 0.1 inch compression and the test will then be

discontinued.

_Hardness_: The tool shown in Fig. 43 (an adaptation of the

apparatus used by the German investigator, Janka) will be used.

The rate of descent of the moving head will be 0.25 inch per

minute. When the penetration has progressed to the point at

which the plate "_a_" becomes tight, due to being pressed

against the wood, the load will be read and recorded.

Two penetrations will be made on a tangential surface, two on a

radial, and one on each end of each specimen tested. The choice

between the two radial and between the two tangential surfaces

and the distribution of the penetrations over the surfaces will

be so made as to get a fair average of heart and sap, slow and

fast growth, and spring and summer wood. Specimens will be 2" X

2" X 6".

_Shear_: The tests will be made with a tool slightly modified

from that shown in Circular 38. The speed of descent of head

will be 0.015 inch per minute. The only measurements to be made

are those of the shearing area. The offset will be 1/8 inch.

Specimens will be 2" X 2" X 2-1/2" in size. (For definition of

offset and form of test specimen, see Fig. 38.)

_Cleavage_: The cleavage tests will be made on specimens of the

form and size shown in Fig. 45. The apparatus will be as shown

in Fig. 44. The maximum load only will be taken and the result

expressed in pounds per inch of width. The speed of the moving

head will be 0.25 inch per minute.

_Moisture Determinations_

Moisture determinations will be made on all specimens tested

except those to be photographed or kept for exhibit. A 1-inch

disk will be cut from near the point of failure of bending and

compression parallel specimens, from the portion under the plate

in the case of the compression perpendicular specimens, and from

the centre of the hardness test specimens. The beads from the

shear specimens will be used as moisture disks. In the case of

the cleavage specimens a piece 1/2 inch thick will be split off

parallel to the failure and used as a moisture disk.

RECORDS

All records will be standard.

PHOTOGRAPHS

_Cross Sections_

Just before cutting into sticks, the freshly cut end of at least

one bolt from each tree will be photographed. A scale of inches

will be shown in this photograph.

_Specimens_

Three photographs will be made of a group consisting of four 2"

X 2" X 30" specimens chosen from the material from each

locality. Two of these specimens will be representative of

average growth, one of fast and one of slow growth. These

photographs will show radial, tangential, and end surfaces for

each specimen.

_Failures_

Typical and abnormal failures of material from each site will be

photographed.

_Disposition of Material_

The specimens photographed to show typical and abnormal failures

will be saved for purposes of exhibit until deemed by the person

in charge of the laboratory to be of no further value.

SHRINKAGE AND SPECIFIC GRAVITY

Appendix to Working Plan 124

PURPOSE OF WORK

It is the purpose of this work to secure data on the shrinkage

and specific gravity of woods tested under Project 124. The

figures to be obtained are for use as average working values

rather than as the basis for a detailed study of the principles

involved.

MATERIAL

The material will be taken from that provided for mechanical

tests.

RADIAL AND TANGENTIAL SHRINKAGE

_Specimens_

_Preparation_: Two specimens 1 inch thick, 4 inches wide, and 1

inch long will be obtained from near the periphery of each "_d_"

bolt. These will be cut from the sector-shaped sections left

after securing the material for the mechanical tests or from

disks cut from near the end of the bolt. They will be taken from

adjoining pieces chosen so that the results will be comparable

for use in determining radial and tangential shrinkage. (When a

disk is used, care must be taken that it is green and has not

been affected by the shrinkage and checking near the end of the

bolt.)

One of these specimens will be cut with its width in the radial

direction and will be used for the determination of radial

shrinkage. The other will have its width in the tangential

direction and will be used for tangential shrinkage. These

specimens will not be surfaced.

_Marking_: The shrinkage specimens will retain the shipment and

piece numbers and marks of the bolts from which they are taken,

and will have the additional mark _7_R or _7_T according as

their widths are in the radial or tangential direction.

_Shrinkage measurements_: The shrinkage specimens will be

carefully weighed and measured soon after cutting. Rings per

inch, per cent sap, and per cent summer wood will be measured.

They will then be air-dried in the laboratory to constant

weight, and afterward oven-dried at 100°C. (212°F.), when they

will again be weighed and measured.

VOLUMETRIC SHRINKAGE AND SPECIFIC GRAVITY

_Specimens_

_Selection and preparation_: Four 2" X 2" X 6" specimens will be

cut from the mechanical test sticks of each "_d_" bolt; also

from each of the composite bolts used in getting a comparison of

green and air-dry. One of these specimens will be taken from

near the pith and one from near the periphery; the other two

will be representative of the average growth of the bolt. The

sides of these specimens will be surfaced and the ends smooth

sawn.

_Marking_: Each specimen will retain the shipment, piece, and

stick numbers and mark of the stick from which it is cut, and

will have the additional mark "_S_."

_Manipulation_: Soon after cutting, each specimen will be

weighed and its volume will be determined by the method

described below. The rings per inch and per cent summer wood,

where possible, will be determined, and a carbon impression of

the end of the specimen made. It will then be air-dried in the

laboratory to a constant weight and afterward oven-dried at

100°C. When dry, the specimen will be taken from the oven,

weighed, and a carbon impression of its end made. While still

warm the specimen will be dipped in hot paraffine. The volume

will then be determined by the following method:

On one pan of a pair of balances is placed a container having in

it water enough for the complete submersion of the test

specimen. This container and water is balanced by weights placed

on the other scale pan. The specimen is then held completely

submerged and not touching the container while the scales are

again balanced. The weight required to balance is the weight of

water displaced by the specimen, and hence if in grams is

numerically equal to the volume of the specimen in cubic

centimetres. A diagrammatic sketch of the arrangement of this

apparatus is shown in Fig. 51.

[Illustration: FIG. 51.--Diagram of specific gravity apparatus,

showing a balance with container (_c_) filled with water in

which the test block (_b_) is held submerged by a light rod

(_a_) which is adjustable vertically and provided with a sharp

point to be driven into the specimen.]

Air-dry specimens will be dipped in water and then wiped dry

after the first weighing and just before being immersed for

weighing their displacement. All displacement determinations

will be made as quickly as possible in order to minimize the

absorption of water by the specimen.

STRENGTH VALUES FOR STRUCTURAL TIMBERS

(From Cir. 189, U.S. Forest Service)

The following tables bring together in condensed form the

average strength values resulting from a large number of tests

made by the Forest Service on the principal structural timbers

of the United States. These results are more completely

discussed in other publications of the Service, a list of which

is given in BIBLIOGRAPHY, PART III.

The tests were made at the laboratories of the U.S. Forest

Service, in cooperation with the following institutions: Yale

Forest School, Purdue University, University of California,

University of Oregon, University of Washington, University of

Colorado, and University of Wisconsin.

Tables XVIII and XIX give the average results obtained from

tests on green material, while Tables XX and XXI give average

results from tests on air-seasoned material. The small

specimens, which were invariably 2" X 2" in cross section, were

free from defects such as knots, checks, and cross grain; all

other specimens were representative of material secured in the

open market. The relation of stresses developed in different

structural forms to those developed in the small clear specimens

is shown for each factor in the column headed "Ratio to 2" X

2"." Tests to determine the mechanical properties of different

species are often confined to small, clear specimens. The ratios

included in the tables may be applied to such results in order

to approximate the strength of the species in structural sizes,

and containing the defects usually encountered, when tests on

such forms are not available.

A comparison of the results of tests on seasoned material with

those from tests on green material shows that, without

exception, the strength of the 2" X 2" specimens is increased by

lowering the moisture content, but that increase in strength of

other sizes is much more erratic. Some specimens, in fact, show

an apparent loss in strength due to seasoning. If structural

timbers are seasoned slowly, in order to avoid excessive

checking, there should be an increase in their strength. In the

light of these facts it is not safe to base working stresses on

results secured from any but green material. For a discussion of

factors of safety and safe working stresses for structural

timbers see the Manual of the American Railway Engineering

Association, Chicago, 1911. A table from that publication,

giving working unit stresses for structural timber, is

reproduced in this book, see Table XXII.

|-----------------------------------------------------------------------------------------------------------------------------------|

| TABLE XVIII TABLE XVIII |

|-----------------------------------------------------------------------------------------------------------------------------------|

| BENDING TESTS ON GREEN MATERIAL |

|-----------------------------------------------------------------------------------------------------------------------------------|

| |-----------------| Num- | Per | Rings | | | | shear |

| Species | | | ber | cent | per |-----------------+-----------------+-----------------+-----------------|

| | | | | | | inch | by 2" | inch | by 2" | inch | by 2" | inch | by 2" |

|-----------------+----------+------+-------+-------+-------+---------+-------+---------+-------+---------+-------+---------+-------|

| | | | | | | | | | | 1,000 | | | |

| | Inches | Ins. | | | | Lbs. | | Lbs. | | lbs. | | Lbs. | |

| | | | | | | | | | | | | | |

| Longleaf pine | 12 by 12 | 138 | 4 | 28.6 | 9.7 | 4,029 | 0.83 | 6,710 | 0.74 | 1,523 | 0.99 | 261 | 0.86 |

| | 10 by 16 | 168 | 4 | 26.8 | 16.7 | 6,453 | .85 | 6,453 | .71 | 1,626 | 1.05 | 306 | 1.01 |

| | 8 by 16 | 156 | 7 | 28.4 | 14.6 | 3,147 | .64 | 5,439 | .60 | 1,368 | .89 | 390 | 1.29 |

| | 6 by 16 | 132 | 1 | 40.3 | 21.8 | 4,120 | .83 | 6,460 | .71 | 1,190 | .77 | 378 | 1.25 |

| | 6 by 10 | 180 | 1 | 31.0 | 6.2 | 3,580 | .72 | 6,500 | .72 | 1,412 | .92 | 175 | .58 |

| | 6 by 8 | 180 | 2 | 27.0 | 8.2 | 3,735 | .75 | 5,745 | .63 | 1,282 | .83 | 121 | .40 |

| | 2 by 2 | 30 | 15 | 33.9 | 14.1 | 4,950 | 1.00 | 9,070 | 1.00 | 1,540 | 1:00 | 303 | 1.00 |

| Douglas fir | 8 by 16 | 180 | 191 | 31.5 | 11.0 | 3,968 | .76 | 5,983 | .72 | 1,517 | .95 | 269 | .81 |

| | 5 by 8 | 180 | 84 | 30.1 | 10.8 | 3,693 | .71 | 5,178 | .63 | 1,533 | .96 | 172 | .52 |

| | 2 by 12 | 180 | 27 | 35.7 | 20.3 | 3,721 | .71 | 5,276 | .64 | 1,642 | 1.03 | 256 | .77 |

| | 2 by 10 | 180 | 26 | 32.9 | 21.6 | 3,160 | .60 | 4,699 | .57 | 1,593 | 1.00 | 189 | .57 |

| | 2 by 8 | 180 | 29 | 33.6 | 17.6 | 3,593 | .69 | 5,352 | .65 | 1,607 | 1.01 | 171 | .51 |

| | 2 by 2 | 24 | 568 | 30.4 | 11.6 | 5,227 | 1.00 | 9,070 | 1.00 | 1,540 | 1.00 | 303 | 1.00 |

| (fire-killed) | 8 by 16 | 180 | 30 | 36.8 | 10.9 | 3,503 | .80 | 4,994 | .64 | 1,531 | .94 | 330 | 1.19 |

| | 2 by 12 | 180 | 32 | 34.2 | 17.7 | 3,489 | .80 | 5,085 | .66 | 1,624 | .99 | 247 | .89 |

| | 2 by 10 | 180 | 32 | 38.9 | 18.1 | 3,851 | .88 | 5,359 | .69 | 1,716 | 1.05 | 216 | .78 |

| | 2 by 8 | 180 | 31 | 37.0 | 15.7 | 3,403 | .78 | 5,305 | .68 | 1,676 | 1.02 | 169 | .61 |

| | 2 by 2 | 30 | 290 | 33.2 | 17.2 | 4,360 | 1.00 | 7,752 | 1.00 | 1,636 | 1.00 | 277 | 1.00 |

| Shortleaf pine | 8 by 16 | 180 | 12 | 39.5 | 12.1 | 3,185 | .73 | 5,407 | .70 | 1,438 | 1.03 | 362 | 1.40 |

| | 8 by 14 | 180 | 12 | 45.8 | 12.7 | 3,234 | .74 | 5,781 | .75 | 1,494 | 1.07 | 338 | 1.31 |

| | 8 by 12 | 180 | 24 | 52.2 | 11.8 | 3,265 | .75 | 5,503 | .71 | 1,480 | 1.06 | 277 | 1.07 |

| | 5 by 8 | 180 | 24 | 47.8 | 11.5 | 3,519 | .81 | 5,732 | .74 | 1,485 | 1.06 | 185 | .72 |

| | 2 by 2 | 30 | 254 | 51.7 | 13.6 | 4,350 | 1.00 | 7,710 | 1.00 | 1,395 | 1.00 | 258 | 1.00 |

| Western larch | 8 by 16 | 180 | 32 | 51.0 | 25.3 | 3,276 | .77 | 4,632 | .64 | 1,272 | .97 | 298 | 1.11 |

| | 8 by 12 | 180 | 30 | 50.3 | 23.2 | 3,376 | .79 | 5,286 | .73 | 1,331 | 1.02 | 254 | .94 |

| | 5 by 8 | 180 | 14 | 56.0 | 25.6 | 3,528 | .83 | 5,331 | .74 | 1,432 | 1.09 | 169 | .63 |

| | 2 by 2 | 28 | 189 | 46.2 | 26.2 | 4,274 | 1.00 | 7,251 | 1.00 | 1,310 | 1.00 | 269 | 1.00 |

| Loblolly pine | 8 by 16 | 180 | 17 | 15.8 | 6.1 | 3,094 | .75 | 5,394 | .69 | 1,406 | .98 | 383 | 1.44 |

| | 5 by 12 | 180 | 94 | 60.9 | 5.9 | 3,030 | .74 | 5,028 | .64 | 1,383 | .96 | 221 | .83 |

| | 2 by 2 | 30 | 44 | 70.9 | 5.4 | 4,100 | 1.00 | 7,870 | 1.00 | 1,440 | 1.00 | 265 | 1.00 |

| Tamarack | 6 by 12 | 162 | 15 | 57.6 | 16.6 | 2,914 | .75 | 4,500 | .66 | 1,202 | 1.05 | 255 | 1.11 |

| | 4 by 10 | 162 | 15 | 43.5 | 11.4 | 2,712 | .70 | 4,611 | .68 | 1,238 | 1.08 | 209 | .91 |

| | 2 by 2 | 30 | 82 | 38.8 | 14.0 | 3,875 | 1.00 | 6,820 | 1.00 | 1,141 | 1.00 | 229 | 1.00 |

| Western hemlock | 8 by 16 | 180 | 39 | 42.5 | 15.6 | 3,516 | .80 | 5,296 | .73 | 1,445 | 1.01 | 261 | .92 |

| | 2 by 2 | 28 | 52 | 51.8 | 12.1 | 4.406 | 1.00 | 7,294 | 1.00 | 1,428 | 1.00 | 284 | 1.00 |

| Redwood | 8 by 16 | 180 | 14 | 86.5 | 19.9 | 3,734 | .79 | 4,492 | .64 | 1,016 | .96 | 300 | 1.21 |

| | 6 by 12 | 180 | 14 | 87.3 | 17.8 | 3,787 | .80 | 4,451 | .64 | 1,068 | 1.00 | 224 | .90 |

| | 7 by 9 | 180 | 14 | 79.8 | 16.7 | 4,412 | .93 | 5,279 | .76 | 1,324 | 1.25 | 199 | .80 |

| | 3 by 14 | 180 | 13 | 86.1 | 23.7 | 3,506 | .74 | 4,364 | .62 | 947 | .89 | 255 | 1.03 |

| | 2 by 12 | 180 | 12 | 70.9 | 18.6 | 3,100 | .65 | 3,753 | .54 | 1,052 | .99 | 187 | .75 |

| | 2 by 10 | 180 | 13 | 55.8 | 20.0 | 3,285 | .69 | 4,079 | .58 | 1,107 | 1.04 | 169 | .68 |

| | 2 by 8 | 180 | 13 | 63.8 | 21.5 | 2,989 | .63 | 4,063 | .58 | 1,141 | 1.08 | 134 | .54 |

| | 2 by 2 | 28 | 157 | 75.5 | 19.1 | 4,750 | 1.00 | 6,980 | 1.00 | 1,061 | 1.00 | 248 | 1.00 |

| Norway pine | 6 by 12 | 162 | 15 | 50.3 | 12.5 | 2,305 | .82 | 3,572 | .69 | 987 | 1.03 | 201 | 1.17 |

| | 4 by 12 | 162 | 18 | 47.9 | 14.7 | 2,648 | .94 | 4,107 | .79 | 1,255 | 1.31 | 238 | 1.38 |

| | 4 by 10 | 162 | 16 | 45.7 | 13.3 | 2,674 | .95 | 4,205 | .81 | 1,306 | 1.36 | 198 | 1.15 |

| | 2 by 2 | 30 | 133 | 32.3 | 11.4 | 2,808 | 1.00 | 5,173 | 1.00 | 960 | 1.00 | 172 | 1.00 |

| Red spruce | 2 by 10 | 144 | 14 | 32.5 | 21.9 | 2,394 | .66 | 3,566 | .60 | 1,180 | 1.02 | 181 | .80 |

| | 2 by 2 | 26 | 60 | 37.3 | 21.3 | 3,627 | 1.00 | 5,900 | 1.00 | 1,157 | 1.00 | 227 | 1.00 |

| White spruce | 2 by 10 | 144 | 16 | 40.7 | 9.3 | 2,239 | .72 | 3,288 | .63 | 1,081 | 1.08 | 166 | .83 |

| | 2 by 2 | 26 | 83 | 58.3 | 10.2 | 3.090 | 1.00 | 5,185 | 1.00 | 998 | 1.00 | 199 | 1.00 |

|-----------------------------------------------------------------------------------------------------------------------------------|

| _Note.--Following is an explanation of the abbreviations used in the foregoing tables:_ |

| F.S. at E.L. = Fiber stress at elastic limit. |

| M. of E. = Modulus of elasticity. |

| M. of R. = Modulus of rupture. |

| Cr. str. at E.L. = Crushing strength at elastic limit. |

| Cr. str. at max. ld. = Crushing strength at maximum load. |

|-----------------------------------------------------------------------------------------------------------------------------------|

|-----------------------------------------------------------------------------------------------------------------------------------------------|

| TABLE XIX TABLE XIX |

|-----------------------------------------------------------------------------------------------------------------------------------------------|

| COMPRESSION AND SHEAR TESTS ON GREEN MATERIAL |

|-----------------------------------------------------------------------------------------------------------------------------------------------|

| |------------------------------------------------------+-------------------------------------------+--------------------------|

| | | | | Cr. | | Cr. | | | | | Cr. | | | |

| Species | | | Per | str. | M. of | str. | | | | Per | str. | | Per | |

| | specimen | of | of | E. L. | per | ld.,. | area | Height | of | of | ld., | of | of | strength |

|-----------------+----------+-------+-------+--------+--------+---------+--------+--------+-------+ ------+---------+-------+-------+----------|

| | | | | | 1,000 | | | | | | | | | |

| | Inches | | | Lbs. | lbs. | Lbs. | Inches | Inches | | | Lbs. | | | Lbs. |

| | | | | | | | | | | | | | | |

| Longleaf pine | 4 by 4 | 46 | 26.3 | 3,480 | | 4,800 | 4 by 4 | 4 | 22 | 25.3 | 568 | 44 | 21.8 | 973 |

| | 2 by 2 | 14 | 34.7 | | | 4,400 | | | | | | | | |

| Douglas fir | 6 by 6 | 515 | 30.7 | 2,780 | 1,181 | 3,500 | 4 by 8 | 16 | 259 | 30.3 | 570 | 531 | 29.7 | 765 |

| | 5 by 6 | 170 | 30.9 | 2,720 | 2,123 | 3,490 | | | | | | | | |

| | 2 by 2 | 902 | 29.8 | 3,500 | 1,925 | 4,030 | | | | | | | | |

| (fire-killed) | 6 by 6 | 108 | 34.8 | 2,620 | 1,801 | 3,290 | 6 by 8 | 16 | 24 | 33.7 | 368 | 77 | 35.8 | 631 |

| | 2 by 2 | 204 | 37.9 | | | 3,430 | | | | | | | | |

| Shortleaf pine | 6 by 6 | 95 | 41.2 | 2,514 | 1,565 | 3,436 | 5 by 8 | 16 | 12 | 37.7 | 361 | 179 | 47.0 | 704 |

| | 5 by 8 | 23 | 43.5 | 2,241 | 1,529 | 3,423 | 5 by 8 | 14 | 12 | 42.8 | 366 | | | |

| | 2 by 2 | 281 | 51.4 | | | 3,570 | 5 by 8 | 12 | 24 | 53.0 | 325 | | | |

| | | | | | | | 5 by 5 | 8 | 24 | 47.0 | 344 | | | |

| | | | | | | | 2 by 2 | 2 | 277 | 48.5 | 400 | | | |

| Western larch | 6 by 6 | 107 | 49.1 | 2,675 | 1,575 | 3,510 | 6 by 8 | 16 | 22 | 43.6 | 417 | 179 | 40.7 | 700 |

| | 2 by 2 | 491 | 50.6 | 3,026 | 1,545 | 3,696 | 6 by 8 | 12 | 20 | 40.2 | 416 | | | |

| | | | | | | | 4 by 6 | 6 | 53 | 52.8 | 478 | | | |

| | | | | | | | 4 by 4 | 4 | 30 | 50.4 | 472 | | | |

| Loblolly pine | 8 by 8 | 14 | 63.4 | 1,560 | 365 | 2,140 | 8 by 4 | 8 | 16 | 67.2 | 392 | 121 | 83.2 | 630 |

| | 4 by 8 | 18 | 60.0 | 2,430 | 691 | 3,560 | 4 by 4 | 8 | 38 | 44.6 | 546 | | | |

| | 2 by 2 | 53 | 74.0 | | | 3,240 | | | | | | | | |

| Tamarack | 6 by 7 | 4 | 49.9 | 2,332 | 1,432 | 3,032 | | | | | | 24 | 39.2 | 668 |

| | 4 by 7 | 6 | 27.7 | 2,444 | 1,334 | 3,360 | | | | | | | | |

| | 2 by 2 | 165 | 36.8 | | | 3,190 | | | | | | | | |

| Western hemlock | 6 by 6 | 82 | 46.6 | 2,905 | 1,617 | 3,355 | 6 by 4 | 6 | 30 | 48.7 | 434 | 54 | 65.7 | 630 |

| | 2 by 2 | 131 | 55.6 | 2,938 | 1,737 | 3,392 | | | | | | | | |

| Redwood | 6 by 6 | 34 | 83.6 | 3,194 | 1,240 | 3,882 | 6 by 8 | 16 | 13 | 86.7 | 473 | 148 | 84.2 | 742 |

| | 2 by 2 | 143 | 36.8 | 3,490 | 1,222 | 3,980 | 6 by 6 | 12 | 14 | 83.0 | 424 | | | |

| | | | | | | | 6 by 7 | 9 | 13 | 74.7 | 477 | | | |

| | | | | | | | 6 by 3 | 14 | 13 | 75.6 | 411 | | | |

| | | | | | | | 6 by 2 | 12 | 12 | 66.5 | 430 | | | |

| | | | | | | | 6 by 2 | 10 | 11 | 55.0 | 423 | | | |

| | | | | | | | 6 by 2 | 8 | 12 | 56.7 | 396 | | | |

| | | | | | | | 2 by 2 | 2 | 186 | 75.5 | 569 | | | |

| Norway pine | 6 by 7 | 5 | 29.0 | 1,928 | 905 | 2,404 | | | | | | 20 | 26.7 | 589 |

| | 4 by 7 | 8 | 28.4 | 2,154 | 1,063 | 2,652 | | | | | | | | |

| | 2 by 2 | 178 | 26.8 | | | 2,504 | | | | | | | | |

| Red spruce | 2 by 2 | 58 | 35.4 | | | 2,750 | 2 by 2 | 2 | 43 | 31.8 | 310 | 30 | 32.0 | 758 |

| White spruce | 2 by 2 | 84 | 61.0 | | | 2,370 | 2 by 2 | 2 | 46 | 50.4 | 270 | 40 | 58.0 | 651 |

|-----------------------------------------------------------------------------------------------------------------------------------------------|

| _Note.--Following is an explanation of the abbreviations used in the foregoing tables:_ |

| F.S. at E.L. = Fiber stress at elastic limit. |

| M. of E. = Modulus of elasticity. |

| M. of R. = Modulus of rupture. |

| Cr. str. at E.L. = Crushing strength at elastic limit. |

| Cr. str. at max. ld. = Crushing strength at maximum load. |

|-----------------------------------------------------------------------------------------------------------------------------------------------|

|-----------------------------------------------------------------------------------------------------------------------------------|

| TABLE XX TABLE XX |

|-----------------------------------------------------------------------------------------------------------------------------------|

| BENDING TESTS ON AIR-SEASONED MATERIAL |

|-----------------------------------------------------------------------------------------------------------------------------------|

| |-----------------| Num- | Per | Rings | | | | shear |

| Species | | | ber | cent | per |-----------------+-----------------+-----------------+-----------------|

| | | | | | | inch | by 2" | inch | by 2" | inch | by 2" | inch | by 2" |

|-----------------+----------+------+-------+-------+-------+---------+-------+---------+-------+---------+-------+---------+-------|

| | | | | | | | | | | 1,000 | | | |

| | Inches | Ins. | | | | Lbs. | | Lbs. | | lbs. | | Lbs. | |

| | | | | | | | | | | | | | |

| Longleaf pine | 8 by 16 | 180 | 5 | 22.2 | 16.0 | 3,390 | 0.50 | 4,274 | 0.37 | 1,747 | 1.00 | 288 | 0.75 |

| | 6 by 16 | 132 | 1 | 23.4 | 17.1 | 3,470 | .51 | 6,610 | .57 | 1,501 | .86 | 388 | 1.01 |

| | 6 by 10 | 177 | 2 | 19.0 | 8.8 | 4,560 | .68 | 7,880 | .68 | 1,722 | .99 | 214 | .56 |

| | 4 by 11 | 180 | 1 | 18.4 | 23.9 | 3,078 | .46 | 8,000 | .69 | 1,660 | .95 | 251 | .66 |

| | 6 by 8 | 177 | 6 | 20.0 | 13.7 | 4,227 | .63 | 8,196 | .71 | 1,634 | .94 | 177 | .46 |

| | 2 by 2 | 30 | 17 | 15.9 | 13.9 | 6,750 | 1.00 | 11,520 | 1.00 | 1,740 | 1.00 | 383 | 1.00 |

| Douglas fir | 8 by 16 | 180 | 91 | 20.8 | 13.1 | 4,563 | .68 | 6,372 | .61 | 1,549 | .91 | 269 | .64 |

| | 5 by 8 | 180 | 30 | 14.9 | 12.2 | 5,065 | .76 | 6,777 | .65 | 1,853 | 1.09 | 218 | .52 |

| | 2 by 2 | 24 | 211 | 19.0 | 16.4 | 6,686 | 1.00 | 10,378 | 1.00 | 1,695 | 1.00 | 419 | 1.00 |

| Shortleaf pine | 8 by 16 | 180 | 3 | 17.0 | 12.3 | 4,220 | .54 | 6,030 | .50 | 1,517 | .85 | 398 | .98 |

| | 8 by 14 | 180 | 3 | 16.0 | 12.3 | 4,253 | .55 | 5,347 | .44 | 1,757 | .98 | 307 | .76 |

| | 8 by 12 | 180 | 7 | 16.0 | 12.4 | 5,051 | .65 | 7,331 | .60 | 1,803 | 1.01 | 361 | .89 |

| | 5 by 8 | 180 | 6 | 12.2 | 22.5 | 7,123 | .92 | 9,373 | .77 | 1,985 | 1.11 | 301 | .74 |

| | 2 by 2 | 30 | 67 | 14.2 | 13.7 | 7,780 | 1.00 | 12,120 | 1.00 | 1,792 | 1.00 | 404 | 1.00 |

| Western larch | 8 by 16 | 180 | 23 | 18.3 | 21.9 | 3,343 | .57 | 5,440 | .53 | 1,409 | .90 | 349 | .96 |

| | 8 by 12 | 180 | 29 | 17.8 | 23.4 | 3,631 | .62 | 6,186 | .60 | 1,549 | .99 | 295 | .81 |

| | 5 by 8 | 180 | 10 | 13.6 | 27.6 | 4,730 | .80 | 7,258 | .71 | 1,620 | 1.04 | 221 | .61 |

| | 2 by 2 | 30 | 240 | 16.1 | 26.8 | 5,880 | 1.00 | 10,254 | 1.00 | 1,564 | 1.00 | 364 | 1.00 |

| Loblolly pine | 8 by 16 | 180 | 14 | 20.5 | 7.4 | 4,195 | .81 | 6,734 | .72 | 1,619 | 1.10 | 462 | 1.45 |

| | 6 by 16 | 126 | 4 | 20.2 | 5.0 | 2,432 | .47 | 4,295 | .46 | 1,324 | .90 | 266 | .84 |

| | 6 by 10 | 174 | 3 | 21.3 | 4.7 | 3,100 | .60 | 6,167 | .66 | 1,449 | .99 | 173 | .54 |

| | 4 by 12 | 174 | 4 | 19.8 | 4.7 | 2,713 | .52 | 5,745 | .61 | 1,249 | .85 | 185 | .58 |

| | 8 by 8 | 180 | 9 | 22.9 | 4.9 | 2,903 | .56 | 4,557 | .48 | 1,136 | .77 | 93 | .29 |

| | 6 by 7 | 144 | 2 | 21.1 | 5.0 | 2,990 | .58 | 4,968 | .53 | 1,286 | .88 | 116 | .36 |

| | 4 by 8 | 132 | 8 | 19.5 | 9.1 | 3,384 | .65 | 6,194 | .66 | 1,200 | .82 | 196 | .62 |

| | 2 by 2 | 30 | 123 | 17.6 | 6.6 | 5,170 | 1.00 | 9,400 | 1.00 | 1,467 | 1.00 | 318 | 1.00 |

| Tamarack | 6 by 12 | 162 | 5 | 23.0 | 15.1 | 3,434 | .45 | 5,640 | .43 | 1,330 | .82 | 318 | .75 |

| | 4 by 10 | 162 | 4 | 14.4 | 9.7 | 4,100 | .54 | 5,320 | .41 | 1,386 | .84 | 252 | .59 |

| | 2 by 2 | 30 | 47 | 11.3 | 16.2 | 7,630 | 1.00 | 13,080 | 1.00 | 1,620 | 1.00 | 425 | 1.00 |

| Western hemlock | 8 by 16 | 180 | 44 | 17.7 | 17.8 | 4,398 | .69 | 6,420 | .62 | 1,737 | 1.04 | 406 | 1.06 |

| | 2 by 2 | 28 | 311 | 17.9 | 19.4 | 6,333 | 1.00 | 10,369 | 1.00 | 1,666 | 1.00 | 382 | 1.00 |

| Redwood | 8 by 16 | 180 | 6 | 26.3 | 22.4 | 3,797 | .79 | 4,428 | .57 | 1,107 | .96 | 294 | 1.05 |

| | 6 by 12 | 180 | 6 | 16.1 | 17.7 | 3,175 | .66 | 3,353 | .43 | 728 | .64 | 167 | .60 |

| | 7 by 9 | 180 | 6 | 15.9 | 15.2 | 3,280 | .69 | 4,002 | .51 | 1,104 | .96 | 147 | .53 |

| | 3 by 14 | 180 | 6 | 13.1 | 24.4 | | | 5,033 | .64 | | | 291 | 1.04 |

| | 2 by 12 | 180 | 5 | 13.8 | 14.4 | 3,928 | .82 | 5,336 | .68 | 1,249 | 1.09 | 260 | .93 |

| | 2 by 10 | 180 | 5 | 13.8 | 24.8 | 3,757 | .79 | 4,606 | .59 | 1,198 | 1.05 | 186 | .67 |

| | 2 by 8 | 180 | 6 | 13.7 | 20.7 | 4,314 | .90 | 5,050 | .65 | 1,313 | 1.15 | 166 | .60 |

| | 2 by 2 | 28 | 122 | 15.2 | 18.8 | 4,777 | 1.00 | 7,798 | 1.00 | 1,146 | 1.00 | 279 | 1.00 |

| Norway pine | 6 by 12 | 162 | 5 | 16.7 | 8.1 | 2,968 | .56 | 5,204 | .61 | 1,123 | .97 | 286 | 1.02 |

| | 4 by 10 | 162 | 5 | 13.7 | 12.0 | 5,170 | .98 | 6,904 | .82 | 1,712 | 1.48 | 317 | 1.13 |

| | 2 by 2 | 30 | 60 | 14.9 | 11.2 | 5,280 | 1.00 | 8,470 | 1.00 | 1,158 | 1.00 | 281 | 1.00 |

|-----------------------------------------------------------------------------------------------------------------------------------|

| _Note.--Following is an explanation of the abbreviations used in the foregoing tables:_ |

| F.S. at E.L. = Fiber stress at elastic limit. |

| M. of E. = Modulus of elasticity. |

| M. of R. = Modulus of rupture. |

| Cr. str. at E.L. = Crushing strength at elastic limit. |

| Cr. str. at max. ld. = Crushing strength at maximum load. |

|-----------------------------------------------------------------------------------------------------------------------------------|

|-----------------------------------------------------------------------------------------------------------------------------------------------|

| TABLE XXI TABLE XXI |

|-----------------------------------------------------------------------------------------------------------------------------------------------|

| COMPRESSION AND SHEAR TESTS ON AIR-SEASONED MATERIAL |

|-----------------------------------------------------------------------------------------------------------------------------------------------|

| |------------------------------------------------------+-------------------------------------------+--------------------------|

| | | | | Cr. | | Cr. | | | | | Cr. | | | |

| Species | | | Per | str. | M. of | str. | | | | Per | str. | | Per | |

| | specimen | of | of | E. L. | per | ld.,. | area | Height | of | of | ld., | of | of | strength |

|-----------------+----------+-------+-------+--------+--------+---------+--------+--------+-------+ ------+---------+-------+-------+----------|

| | | | | | 1,000 | | | | | | | | | |

| | Inches | | | Lbs. | lbs. | Lbs. | Inches | Inches | | | Lbs. | | | Lbs. |

| | | | | | | | | | | | | | | |

| Longleaf pine | 4 by 5 | 46 | 26.3 | 3,480 | | 4,800 | 4 by 5 | 4 | 22 | 25.1 | 572 | 52 | 20.2 | 984 |

| Douglas fir | 6 by 6 | 259 | 20.3 | 3,271 | 1,038 | 4,258 | 4 by 8 | 16 | 44 | 20.8 | 732 | 465 | 22.1 | 822 |

| | 2 by 2 | 247 | 18.7 | 3,842 | 1,084 | 5,002 | 4 by 8 | 10 | 32 | 18.1 | 584 | | | |

| | | | | | | | 4 by 4 | 8 | 51 | 20.2 | 638 | | | |

| | | | | | | | 4 by 4 | 6 | 49 | 24.0 | 613 | | | |

| | | | | | | | 4 by 4 | 4 | 29 | 24.8 | 603 | | | |

| Shortleaf pine | 6 by 6 | 29 | 15.7 | 4,070 | 1,951 | 6,030 | 8 by 5 | 16 | 4 | 17.8 | 725 | 85 | | 1,135 |

| | 2 by 2 | 57 | 14.2 | | | 6,380 | 8 by 5 | 14 | 3 | 16.3 | 757 | | | |

| | | | | | | | 8 by 5 | 12 | 5 | 15.1 | 730 | | | |

| | | | | | | | 5 by 5 | 8 | 6 | 13.0 | 918 | | | |

| | | | | | | | 2 by 2 | 2 | 57 | 13.9 | 926 | | | |

| Western larch | 6 by 6 | 112 | 16.0 | | | 5,445 | 8 by 6 | 16 | 17 | 18.8 | 491 | 193 | 15.0 | 905 |

| | 4 by 4 | 81 | 14.7 | | | 6,161 | 8 by 6 | 12 | 18 | 17.6 | 526 | | | |

| | 2 by 2 | 270 | 14.8 | | | 5,934 | 5 by 4 | 8 | 22 | 13.3 | 735 | | | |

| Loblolly pine | 6 by 6 | 23 | | 3,357 | 1,693 | 5,005 | 8 by 5 | 16 | 12 | 19.8 | 602 | 156 | 11.3 | 1,115 |

| | 5 by 5 | 10 | 22.4 | 2,217 | 545 | 2,950 | 8 by 5 | 8 | 7 | 22.9 | 679 | | | |

| | 4 by 8 | 8 | 19.4 | 3,010 | 633 | 3,920 | 4 by 5 | 8 | 8 | 19.5 | 715 | | | |

| | 2 by 2 | 69 | | | | 5,547 | | | | | | | | |

| Tamarack | 6 by 7 | 3 | 15.7 | 2,257 | 1,042 | 3,323 | 2 by 2 | 2 | 57 | 16.2 | 697 | 60 | 14.0 | 879 |

| | 4 by 7 | 3 | 13.6 | 3,780 | 1,301 | 4,823 | | | | | | | | |

| | 4 by 4 | 57 | 14.9 | 3,386 | 1,353 | 4,346 | | | | | | | | |

| | 2 by 2 | 66 | 14.6 | | | 4,790 | | | | | | | | |

| Western hemlock | 6 by 6 | 102 | 18.6 | 4,840 | 2,140 | 5,814 | 7 by 6 | 15 | 25 | 18.2 | 514 | 131 | 17.7 | 924 |

| | 2 by 2 | 463 | 17.0 | 4,560 | 1,923 | 5,403 | 6 by 6 | 6 | 26 | 16.8 | 431 | | | |

| | | | | | | | 4 by 4 | 4 | 6 | 15.9 | 488 | | | |

| Redwood | 6 by 6 | 18 | 16.9 | | | 4,276 | 8 by 6 | 16 | 5 | 25.4 | 548 | 95 | 12.4 | 671 |

| | 2 by 2 | 115 | 14.6 | | | 5,119 | 6 by 6 | 12 | 6 | 14.7 | 610 | | | |

| | | | | | | | 7 by 6 | 9 | 5 | 14.8 | 500 | | | |

| | | | | | | | 3 by 6 | 14 | 2 | 12.6 | 470 | | | |

| | | | | | | | 2 by 6 | 12 | 2 | 16.2 | 498 | | | |

| | | | | | | | 2 by 6 | 10 | 4 | 14.3 | 511 | | | |

| | | | | | | | 2 by 6 | 8 | 2 | 13.2 | 429 | | | |

| | | | | | | | 2 by 2 | 2 | 145 | 13.8 | 564 | | | |

| Norway pine | 6 by 7 | 4 | 15.2 | 2,670 | 1,182 | 4,212 | 2 by 2 | 2 | 36 | 10.0 | 924 | 44 | 11.9 | 1,145 |

| | 4 by 7 | 2 | 22.2 | 3,275 | 1,724 | 4,575 | | | | | | | | |

| | 4 by 4 | 55 | 16.6 | 3,048 | 1,367 | 4,217 | | | | | | | | |

| | 2 by 2 | 44 | 11.2 | | | 7,550 | | | | | | | | |

|-----------------------------------------------------------------------------------------------------------------------------------------------|

| _Note.--Following is an explanation of the abbreviations used in the foregoing tables:_ |

| F.S. at E.L. = Fiber stress at elastic limit. |

| M. of E. = Modulus of elasticity. |

| M. of R. = Modulus of rupture. |

| Cr. str. at E.L. = Crushing strength at elastic limit. |

| Cr. str. at max. ld. = Crushing strength at maximum load. |

|-----------------------------------------------------------------------------------------------------------------------------------------------|

|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

| TABLE XXII TABLE XXII |

|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

| [b]WORKING UNIT-STRESSES FOR STRUCTURAL TIMBER[c] |

| EXPRESSED IN POUNDS PER SQUARE INCH |

| (From Manual of the American Railway Engineering Assn., 1911, p. 153) |

|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

| NOTE.--The working unit-stresses given in the table are intended for railroad bridges and trestles. For highway bridges and trestles the unit-stresses may be increased |

| twenty-five (25) per cent. For buildings and similar structures, in which the timber is protected from the weather and practically free from impact, the unit-stresses may be |

| increased fifty (50) per cent. To compute the deflection of a beam under long-continued loading instead of that when the load is first applied, only fifty (50) per cent of the |

| corresponding modulus of elasticity given in the table is to be employed. |

|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

| |---------------------------------+-----------------------------------------+-------------------------------------------------------------------------| Ratio |

| TIMBER |--------------------+------------+--------------------+--------------------+--------------------+--------------------| diameters | 15 diameters | stringer |

|-----------------+----------+---------+------------+----------+---------+----------+---------+----------+---------+----------+---------+-----------+-------------------+----------|

| Douglas fir | 6100 | 1200 | 1,510,000 | 690 | 170 | 270 | 110 | 630 | 310 | 3600 | 1200 | 900 | 1200(1-_l_/60_d_) | 10 |

|-----------------+----------+---------+------------+----------+---------+----------+---------+----------+---------+----------+---------+-----------+-------------------+----------|

| Longleaf pine | 6500 | 1300 | 1,610,000 | 720 | 180 | 300 | 120 | 520 | 260 | 3800 | 1300 | 980 | 1300(1-_l_/60_d_) | 10 |

|-----------------+----------+---------+------------+----------+---------+----------+---------+----------+---------+----------+---------+-----------+-------------------+----------|

| Shortleaf pine | 5600 | 1100 | 1,480,000 | 710 | 170 | 330 | 130 | 340 | 170 | 3400 | 1100 | 830 | 1100(1-_l_/60_d_) | 10 |

|-----------------+----------+---------+------------+----------+---------+----------+---------+----------+---------+----------+---------+-----------+-------------------+----------|

| White pine | 4400 | 900 | 1,130,000 | 400 | 100 | 180 | 70 | 290 | 150 | 3000 | 1000 | 750 | 1000(1-_l_/60_d_) | 10 |

|-----------------+----------+---------+------------+----------+---------+----------+---------+----------+---------+----------+---------+-----------+-------------------+----------|

| Spruce | 4800 | 1000 | 1,310,000 | 600 | 150 | 170 | 70 | 370 | 180 | 3200 | 1100 | 830 | 1100(1-_l_/60_d_) | |

|-----------------+----------+---------+------------+----------+---------+----------+---------+----------+---------+----------+---------+-----------+-------------------+----------|

| Norway pine | 4200 | 800 | 1,190,000 | 590[d] | 130 | 250 | 100 | | 150 | 2600[d] | 800 | 600 | 800(1-_l_/60_d_) | |

|-----------------+----------+---------+------------+----------+---------+----------+---------+----------+---------+----------+---------+-----------+-------------------+----------|

| Tamarack | 4600 | 900 | 1,220,000 | 670 | 170 | 260 | 100 | | 220 | 3200[d] | 1000 | 750 | 1000(1-_l_/60_d_) | |

|-----------------+----------+---------+------------+----------+---------+----------+---------+----------+---------+----------+---------+-----------+-------------------+----------|

| Western hemlock | 5800 | 1100 | 1,480,000 | 630 | 160 | 270[d] | 100 | 440 | 220 | 3500 | 1200 | 900 | 1200(1-_l_/60_d_) | |

|-----------------+----------+---------+------------+----------+---------+----------+---------+----------+---------+----------+---------+-----------+-------------------+----------|

| Redwood | 5000 | 900 | 800,000 | 300 | 80 | | | 400 | 150 | 3300 | 900 | 680 | 900(1-_l_/60_d_) | |

|-----------------+----------+---------+------------+----------+---------+----------+---------+----------+---------+----------+---------+-----------+-------------------+----------|

| Bald cypress | 4800 | 900 | 1,150,000 | 500 | 120 | | | 340 | 170 | 3900 | 1100 | 830 | 1100(1-_l_/60_d_) | |

|-----------------+----------+---------+------------+----------+---------+----------+---------+----------+---------+----------+---------+-----------+-------------------+----------|

| Red cedar | 4200 | 800 | 800,000 | | | | | 470 | 230 | 2800 | 900 | 680 | 900(1-_l_/60_d_) | |

|-----------------+----------+---------+------------+----------+---------+----------+---------+----------+---------+----------+---------+-----------+-------------------+----------|

| White oak | 5700 | 1100 | 1,150,000 | 840 | 210 | 270 | 110 | 920 | 450 | 3500 | 1300 | 980 | 1300(1-_l_/60_d_) | 12 |

|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

| These unit-stresses are for a green condition of timber and are _l_ = Length in inches. |

| to be used without increasing the live load stresses for impact. _d_ = Least side in inches. |

|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

|[Footnote b: Adopted, Vol. 1909, pp. 537, 564, 609-611.] |

|[Footnote c: Green timber in exposed work.] |

|[Footnote d: Partially air-dry] |

|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

BIBLIOGRAPHY

Part I: Some general works on mechanics, materials of

construction, and testing of materials.

Part II: Publications and articles on the mechanical properties

of wood, and timber testing.

Part III: Publications of the U.S. Government on the mechanical

properties of wood, and timber testing.

PART 1. SOME GENERAL WORKS ON MECHANICS, MATERIALS OF

CONSTRUCTION, AND TESTING OF MATERIALS

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BURR, WILLIAM H.: The elasticity and resistance of the materials

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HATFIELD, R.G.: Theory of transverse strain. 1877.

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JAMIESON, ANDREW: Strength of materials. (Applied mechanics and

mechanical engineering, Vol. II.) London, 1911.

JOHNSON, J.B.: The materials of construction. New York, 1910.

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LANZA, GAETANO: Applied mechanics. New York, 1901.

MERRIMAN, MANSFIELD: Mechanics of materials. New York, 1912.

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RANKINE, WILLIAM J.M.: A manual of applied mechanics. London,

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THIL, A.: Conclusion de l'étude présentée à la Commission des

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THURSTON, ROBERT H.: A treatise on non-metallic materials of

engineering: stone, timber, fuel, lubricants, etc. (Materials of

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PART II. PUBLICATIONS AND ARTICLES ON THE MECHANICAL PROPERTIES

OF WOOD, AND TIMBER TESTING

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ADAMS, E.E.: Tests to determine the strength of bolted timber

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BAUSCHINGER, JOHANN: Untersuchungen über die Elasticität und

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----: Verhandlungen der Münchener Conferenz und der von ihr

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----: Untersuchungen über die Elasticität und Festigkeit

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of wood. Proc. Int. Assn. Test. Mat., 1906, Disc, 1_e_, pp. 2.

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----: Forest Service tests to determine the influence of

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----: The Forest Products Laboratory: its purpose and work.

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Comparative strength and resistance of various tie timbers.

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Hobart, Tasmania, 1903, pp. 63.

GREGORY, W.B.: Tests of creosoted timber. Trans. Am. Soc. C.E.,

Vol. LXXVI, 1913, pp. 1192-1203. See also _ibid._, Vol. LXX, p.

37.

GRISARD, JULES, et VANDENBERGHE, MAXIMILIEN: Les bois

industriels, indigènes et exotiques; synonymie et description

des espèces, propriétés physiques des bois, qualités, défauts,

usages et emplois. Paris, 189-. From Bul. de la Société

nationale d'acclimatation de France, Vols. XXXVIII-XL.

Hardwoods of Western Australia. Engineering, Vol. LXXXIII, Jan.

11, 1907, pp. 35-37.

HATT, WILLIAM KENDRICK: A Preliminary program for the timber

test work to be undertaken by the Bureau of Forestry, United

States Department of Agriculture. Proc. Am. Soc. Test. Mat.,

Vol. III, 1903, pp. 308-343. Appendix I: Method of determining

the effect of the rate of application of load on the strength of

timber, pp. 325-327; App. II: A discussion on the effect of

moisture on strength and stiffness of timber, together with a

plan of procedure for future tests, pp. 328-334.

HATT, WILLIAM KENDRICK: Relation of timber tests to forest

products. Proc. Int. Assn. Test. Mat., 1906, C 2 _e_, pp. 6.

----: Structural timber. Proc. Western Ry. Club, St. Louis, Mch.

17, 1908.

----: Abstract of report on the present status of timber tests

in the Forest Service, United States Department of Agriculture.

Proc. Int. Assn. Test. Mat., 1909, XVL, pp. 10.

---- and TURNER, W.P.: The Purdue University impact machine.

Proc. Am. Soc. Test. Mat., Vol. VI, 1906, pp. 462-475.

HAUPT, HERMAN: formulæ for the strain upon timber. Center of

gravity of an ungula and semi-cylinder. Jour. Franklin Inst.,

Vol. XIX, 3d series, 1850, pp. 408-413.

HEARDING, W.H.: Report upon experiments ... upon the compressive

power of pine and hemlock timber. Washington, 1872, pp. 12.

HOWE, MALVERD A.: Wood in compression; bearing values for

inclined cuts. Eng. News, Vol. LXVIII, 1912, pp. 190-191.

HOYER, EGBERT: Lehrbuch der vergleichenden mechanischen

Technologie. 1878.

IHLSENG, MANGUS C.: On the modulus of elasticity of some

American woods as determined by vibration. Van Nostrand's Eng.

Mag., Vol. XIX, 1878, pp. 8-9.

----: On a mode of measuring the velocity of sounds in woods.

Am. Jour. Sci. and Arts, Vol. XVII, 1879.

JACCARD, P.: Étude anatomique des bois comprimés. Mitt. d. Schw.

Centralanstalt f. d. forst. Versuchswesen. X. Bd., 1. Hft.,

Zurich, 1910, pp. 53-101.

JANKA, GABRIEL: Untersuchungen über die Elasticität und

Festigkeit der österreichischen Bauhölzer. I. Fichte Südtirols;

II. Fichte von Nordtirol vom Wienerwalde und Erzgebirge; III.

Fichte aus den Karpaten, aus dem Böhmerwalde, Ternovanerwalde

und den Zentralalpen. Technische Qualität des Fichtenholzes im

allgemeinen; IV. Lärche aus dem Wienerwalde, aus Schlesien,

Nord- und Südtirol. Mitt. a. d. forst. Untersuchungswesen

Oesterreichs, Wien, 1900-13.

----: Untersuchungen über Holzqualität. Centralblatt f. d. ges.

Forstwesen. Wien, 1904, pp. 95-115.

----: Ueber neuere holztechnologische Untersuchungen. Oesterr.

Vierteljahresschrift für Forstwesen, Wien, 1906, pp. 248-269.

----: Die Härte des Holzes. Centralblatt f. d. ges. Forstwesen,

Wien, 1906, pp. 193-202; 241-260.

JANKA, GABRIEL: Die Einwirkung von Süss- und Salzwässern auf die

gewerblichen Eigenschaften der Hauptholzarten. I. Teil.

Untersuchungen u. Ergebnisse in mechanisch-technischer Hinsicht.

Mitt. a. d. forst. Versuchswesen Oesterreichs, 33. Hft., Wien,

1907.

----: Results of trials with timber carried out at the Austrian

forestry testing-station at Mariabrunn. Proc. Int. Assn. Test.

Mat., 1906, Disc. 2 _e_, pp. 7.

----: Ueber die an der k. k. forstlichen Versuchsanstalt

Mariabrunnen gewonnenen Resultate der Holzfestigkeitsprüfungen.

Zeitschrift d. Oesterr. Ing. u. Arch. Ver., Wien, Aug. 9, 1907.

----: Ueber Holzhärteprufüng. Centralblatt f. d. ges.

Forstwesen, Wien, 1908, pp. 443-456.

----: Testing the hardness of wood by means of the ball test.

Proc. Int. Assn. Test. Mat., 1912, XXIII_{3}.

JENNY, K.: Untersuchungen über die Festigkeit der Hölzer aus den

Ländern der ungarischen Krone. Budapest, 1873.

JOHNSON, J.B.: Time tests of timber in endwise compression.

Paper before Section D, Am. Assn. for Adv. of Sci., Aug., 1898.

JOHNSON, WALTER B.: Experiments on the adhesion of iron spikes

of various forms when driven into different species of timbers.

Jour. Franklin Inst., Vol. XIX (n.s.), 1837, pp. 281-292.

JULIUS, G.A.: Western Australia timber tests, 1906. The physical

characteristics of the hardwoods of Western Australia. Perth,

1906, pp. 36.

----: Supplement to the Western Australia timber tests, 1906.

The hardwoods of Australia. Perth, 1907, pp. 6.

KARMARSH, CARL: Handbuch der mechanischen Technologie. I. Aufl.,

1837; V. Aufl., 1875; verm. von H. Fisher, 1888.

KIDDER, F.E.: Experiments on the transverse strength of southern

and white pine. Van Nostrand's Eng. Mag., Vol. XXII, 1880, pp.

166-168.

----: Experiments on the strength and stiffness of small spruce

beams. _Ibid._, Vol. XXIV, 1881, pp. 473-477.

----: Experiments on the fatigue of small spruce beams. Jour.

Franklin Inst., Vol. CXIV, 1882, pp. 261-279.

KIDWELL, EDGAR: The efficiency of built-up wooden beams. Trans.

Am. Inst. Min. Eng., Feb., June, 1898.

KIRKALDY, WM. G.: Illustrations of David Kirkaldy's system of

mechanical testing. London, 1891.

KUMMER, FREDERICK A.: The effects of preservative treatment on

the strength of timber. Proc. Am. Soc. Test. Mat., Vol. IV,

1904, pp. 434-438.

LABORDÈRE, P., and ANSTETT, F.: Contribution to the study of

means for improving the strength of wood for pavements. Proc.

Int. Assn. Test. Mat., 1912, XXIII_{4}, pp. 12.

LANZA, GAETANO: An account of certain tests on the transverse

strength and stiffness of large spruce beams. Trans. Am. Soc.

Mech. Eng., Vol. IV, 1882, pp. 119-135. See also Jour. Franklin

Inst., Vol. XCV, 1883, pp. 81-94.

LASLETT, T.: Properties and characteristics of timber. Chatham,

1867.

----: Timber and timber trees, native and foreign. (2d ed.

revised and enlarged by H. Marshall Ward.) London and New York,

1894.

LEA, W.: Tables of strength and deflection of timber. London,

1861.

LEDEBUR, A.: Die Verarbeitung des Holzes auf mechanischem Wege.

1881.

LORENZ, N. VON: Analytische Untersuchung des Begriffes der

Holzhärte. Centralblatt f. d. ges. Forstwesen, Wien, 1909, pp.

348-387.

LUDWIG, PAUL: Die Regelprobe. Ein neues Verfahren zur

Härtebestimmung von Materialien. Berlin. 1908.

MACFARLAND, H.B.: Tests of longleaf pine bridge timbers. Bul.

149, Am. Ry. Eng. Assn., Sept., 1912. See also Eng. News, Dec.

12, 1912, p. 1035.

McKAY, DONALD: On the weight and strength of American

ship-timber. Jour. Franklin Inst., Vol. XXXIX (3d series), 1860,

p. 322.

MALETTE, J.: Essais des bois de construction. Revue Technique,

Apr. 25, 1905.

MANN, JAMES: Australian timber: its strength, durability, and

identification. Melbourne, 1900.

MARTIN, CLARENCE A.: Tests on the relation between cross-bending

and direct compressive strength in timber. Railroad Gazette,

Mch. 13, 1903.

Methods of testing metals and alloys ... Recommended by the

Fourth Congress of the International Association for Testing

Materials, held at Brussels, Sept. 3-6, 1906. London, 1907, pp.

54. Methods of testing wood, pp. 39-49.

MIKOLASCHEK, CARL: Untersuchungen über die Elasticität und

Festigkeit der wichtigsten Bau- und Nutzhölzer. Mitt. a. d.

forstl. Versuchswesen Oesterreiches, II. Bd., 1. Hft., Wien,

1879.

MOELLER, JOSEPH: Die Rohstoffe des Tischler- und

Drechslergewerbes. I. Theil: Das Holz. Kassel, 1883, pp. 68-122.

MOLESWORTH, G.L.: Graphic diagrams of strength of teak beams.

Roorke, 1881.

MORGAN, J.J.: Bending strength of yellow pine timber. Eng.

Record, Vol. LXVII, 1913, pp. 608-609.

MOROTO, K.: Untersuchungen über die Biegungselasticität und

-Festigkeit der japanischen Bauhölzer. Centralblatt f. d. ges.

Forstwesen, Wien, 1908, pp. 346-355.

NORDLINGER, H.: Die technischen Eigenschaften der Hölzer für

Forst- und Baubeamte, Technologen und Gewerbetreibende.

Stuttgart, 1860.

----: Druckfestigkeit des Holzes. 1882.

----: Die gewerblichen Eigenschaften der Hölzer. Stuttgart,

1890.

NORTH, A.T.: The grading of timber on the strength basis.

Address before Western Society of Engineers. Lumber World

Review, May 25, 1914, pp. 27-29.

NORTON, W.A.: Results of experiments on the set of bars of wood,

iron, and steel, after a transverse stress. Van Nostrand's Eng.

Mag., Vol. XVII, 1877, pp. 531-535.

PACCINOTTI E PERI: [Investigations into the elasticity of

timbers.] Il Cimento, Vol. LVIII, 1845.

PALACIO, E.: Tensile tests of timber. La Ingenieria, Buenos

Aires, May 31, 1903, _et seq._

PARENT,--: Expériences sur la résistance des bois de chêne et de

sapin. Mémoires de l'Académie des Sciences, 1707-08.

Propositions relatives à l'établissement d'un precédé uniforme

pour l'essai des qualités techniques des bois. Proc. Int. Assn.

Test. Mat., 1901, Annexe, pp. 13-28.

ROGERS, CHARLES G.: A manual of forest engineering for India.

Vol. I, Calcutta, 1900, pp. 50-91.

RUDELOFF, M.: Der heutige Stand der Holzuntersuchungen. Mitt. a.

d. königlichen tech. Versuchsanstalt, Berlin, IV, 1899.

----: Principles of a standard method of testing wood. Proc.

Int. Assn. Test. Mat., 1906, 23 C, pp. 16.

----: Large _vs._ small test-pieces in testing wood. Proc. Int.

Soc. Test. Mat., 1912, XXIII_{1}, pp. 7.

SARGENT, CHARLES SPRAGUE: Woods of the United States, with an

account of their structure, qualities, and uses. New York, 1885.

SCHNEIDER, A.: Zusammengesetzte Träger. Zeitschrift d. Oesterr.

Ing. u. Arch. Ver., Nov. 24; Dec. 9, 1899.

SCHWAPPACH, A.F.: Beiträge zur Kenntniss der Qualität des

Rotbuchenholzes. Zeitschrift f. Forst- und Jagdwesen, Berlin,

1894, pp. 513-539.

----: Untersuchungen über Raumgewicht und Druckfestigkeit des

Holzes wichtiger Waldbäume. Berlin, 1897-98.

----: Etablissement de méthodes uniformes pour l'essai á la

compression des bois. Proc. Int. Assn. Test. Mat., 1901, Rapport

23, pp. 28.

SEBERT, H.: Notice sur les bois de la Nouvelle Calédonie suivie

de considerations génerates sur les propriétés mécaniques des

bois et sur les precédés employés pour les mesurer. Paris.

SHERMAN, EDWARD C.: Crushing tests on water-soaked timbers. Eng.

News, Vol. LXII, 1909, p. 22.

SNOW, CHARLES H.: The principal species of wood: their

characteristic properties. New York, 1908.

STAUFFER, OTTMAR: Untersuchungen über specifisches

Trockengewicht, sowie anatomisches Verhalten des Holzes der

Birke. München, 1892.

STENS, D.: Ueber die Eigenschaftenimprägnierter Grubenholzer,

insbesondere über ihre Festigkeit. Glückauf, Essen, Mch. 6,

1907.

Strength of wood for pavements. Can. Eng., Toronto, Sept. 12,

1912.

STÜBSCHEN-KISCHNER: Karmarsch-Heerins technisches Wröterbuch. 3.

Aufl., 1886.

TALBOT, ARTHUR N.: Tests of timber beams. Bul. 41, Eng. Exp.

Sta., Univ. of Ill., Urbana, 1910.

Tests of wooden beams made at the Massachusetts Institute of

Technology on spruce, white pine, yellow pine, and oak beams of

commercial sizes. Technology Quarterly, Boston, Vol. VII, 1894.

TETMAJER, L. v.: Zur Frage der Knickungsfestigkeit der

Bauhölzer. Schweizerische Bauzeitung, Bd. 11, Nr. 17.

----: Methoden und Resultate der Prüfung der schweizerischen

Bauhölzer. Mitt. d. Anstalt z. Prüfung v. Baumaterialien am

eidgenössischen Polytechnicum in Zürich. 2. Hft., 1884.

----: Methoden und Resultate der Prüfung der schweizerischen

Bauhölzer. Mitt. d. Materialprüfungs-Anstalt am Schweiz.

Polytechnikum in Zürich. Landesaustellungs-Ausgabe, 2. Hft.,

Zürich, 1896.

THELEN, ROLF: The structural timbers of the Pacific Coast.

Proc. Am. Soc. Test. Mat., Vol. VIII, 1908, pp. 558-567.

THURSTON, R.H.: Torsional resistance of materials determined by

a new apparatus with automatic registry. Jour. Franklin Inst.,

Vol. LXV, 1873, pp. 254-260.

----: On the strength of American timber. _Ibid._, Vol. LXXVIII,

1879, pp. 217-235.

----: Experiments on the strength of yellow pine. _Ibid._, Vol.

LXXIX, 1880, pp. 157-163.

----: Influence of time on bending strength and elasticity.

Proc. Am. Assn. for Adv. Sci., 1881. Also Proc. Inst. C.E., Vol.

LXXI.

----: On the effect of prolonged stress upon the strength and

elasticity of pine timber. Jour. Franklin Inst., Vol. LXXX,

1881, pp. 161-169. THURSTON, R.H.: On Flint's investigations of

Nicaraguan woods. _Ibid._, Vol. XCIV, 1887, pp. 289-315.

TIEMANN, HARRY DONALD: The effect of moisture and other

extrinsic factors upon the strength of wood. Proc. Am. Soc.

Test. Mat., Vol. VII, 1907, pp. 582-594.

----: The effect of the speed of testing upon the strength of

wood and the standardization of tests for speed. _Ibid._, Vol.

VIII, 1908, pp. 541-557.

----: The theory of impact and its application to testing

materials. Jour. Franklin Inst., Vol. CLXVIII, 1909, pp.

235-259; 336-364.

----: Some results of dead load bending tests of timber by means

of a recording deflectometer. Proc. Am. Soc. Test. Mat., Vol.

IX, 1909, pp. 534-548.

TJADEN, M.E.H.: Het Indrukken van Paalkoppen in Kespen. De

Ingenieur, Sept. 11, 1909.

----: Weerstand van Hout loodrecht op de Vezelrichting. _Ibid._,

May, 1911.

----: Buigvastheid van Hout. _Ibid._, May 31, 1913.

TRAUTWINE, JOHN C.: Shearing strength of some American woods.

Jour. Franklin Inst., Vol. CIX, 1880, pp. 105-106.

TREDGOLD, THOMAS: Elementary principles of carpentry. London,

1870.

TURNBULL, W.: A practical treatise on the strength and stiffness

of timber. London, 1833.

Untersuchungen über den Einfluss des Blauwerdens auf die

Festigkeit von Kiefernholz. Mitt. a. d. könig. techn.

Versuchsanstalten, I, 1897.

Verfahren zur Prüfung v. Metallen und Legierungen, von

hydraulischen Bindemitteln, von Holz, von Ton-, Steinzeug- und

Zementröhren. Empfohlen v. dem in Brüssel v. 3-6, IX, 1906,

abgeh. IV. Kongress des internationalen Verbandes f. die

Materialprüfungen der Technik. Wien, 1907.

WARREN, W.H.: Australian timbers. Sydney, 1892.

----: The strength, elasticity, and other properties of New

South Wales hardwood timbers. Sydney, 1911.

----: The strength, elasticity, and other properties of New

South Wales hardwood timbers. Proc. Int. Assn. Test. Mat., 1912,

XXIII_{6}, pp. 9.

----: The properties of New South Wales hardwood timbers.

Builder, London, Nov. 1, 1912.

----: The hardwood timbers of New South Wales, Australia. Jour.

Soc. of Arts, London, Dec. 6, 1912.

WELLINGTON, A.M.: Experiments on impregnated timber. Railroad

Gazette, 1880.

WIJKANDER, ----: Untersuchung der Festigkeitseigenschaften

schwedischer Holzarten in der Materialprüfungsanstalt des

Chalmers'schen Institutes ausgeführt. 1897.

WING, CHARLES B.: Transverse strength of the Douglas fir. Eng.

News, Vol. XXXIII, Mch. 14, 1895.

PART III. PUBLICATIONS OF THE U.S. GOVERNMENT ON THE MECHANICAL

PROPERTIES OF WOOD, AND TIMBER TESTING

MISCELLANEOUS

House Misc. Doc. 42, pt. 9, 47th Cong., 2d sess., 1884. (Vol.

IX, Tenth Census report.) Report on the forests of North America

(exclusive of Mexico). Part II, The Woods of the United States.

House Report No. 1442, 53d Cong., 2d sess. Investigations and

tests of American timber. 1894, pp. 4.

War Dept. Doc. 1. Resolutions of the conventions held at Munich,

Dresden, Berlin, and Vienna, for the purpose of adopting uniform

methods for testing construction materials with regard to their

mechanical properties. By J. Bauschinger. Translated by O.M.

Carter and E.A. Gieseler. 1896, pp. 44.

War Dept. Doc. 11. On tests of construction materials.

Translations from the French and from the German. By O.M. Carter

and E.A. Gieseler. 1896, pp. 84.

House Doc. No. 181, 55th Cong., 3d sess. Report upon the

forestry investigations of the U.S. Department of Agriculture,

1877-1898. By B.E. Fernow, 1899, pp. 401. Contains chapter on

The work in timber physics in the Division of Forestry, by

Filibert Roth, pp. 330-395.

FOREST SERVICE

Cir. 7--The Government timber tests [189-], pp. 4.

Cir. 8--Strength of "boxed" or "turpentine" timber. 1892, pp. 4.

Bul. 6--Timber Physics. Pt. I. Preliminary report. 1. Need of

the investigation. 2. Scope and historical development of the

science of "timber physics." 3. Organization and methods of

timber examinations in the Division of Forestry. By B.E. Fernow,

1892, pp. 57.

Unnumbered Cir.--Instructions for the collection of test pieces

of pines for timber investigations [1893], pp. 4.

Cir. 9--Effect of turpentine gathering on the timber of longleaf

pine. By B.E. Fernow [1893], p. 1.

Bul. 8--Timber physics. Pt. II. Progress report. Results of

investigations on longleaf pine. 1893, pp. 92.

Bul. 10--Timber: an elementary discussion of the characteristics

and properties of wood. By Filibert Roth. 1895, pp. 88.

Bul. 12--Economical designing of timber trestle bridges. By A.L.

Johnson, 1896, pp. 57.

Cir. 12--Southern pine, mechanical and physical properties.

1896, pp. 12.

Cir. 15--Summary of mechanical tests on thirty-two species of

American woods. 1897, pp. 12.

Cir. 18--Progress in timber physics. 1898, pp. 20.

Cir. 19--Progress in timber physics: Bald cypress (_Taxodium

distichum_). By Filibert Roth, 1898, pp. 24.

Y.B. Extr. 288--Tests on the physical properties of woods. By

F.E. Olmstead, 1902, pp. 533-538.

Unnumbered Cir.--Timber tests. [1903], pp. 15.

Unnumbered Cir.--Timber preservation and timber testing at the

Louisiana Purchase Exposition. 1904, pp. 6.

Cir. 32--Progress report on the strength of structural timber.

By W.K. Hatt, 1904, pp. 28.

Bul. 58--The red gum. By Alfred Chittenden. Includes a

discussion of The mechanical properties of red gum wood, by W.K.

Hatt. 1905, pp. 56.

Cir. 38--Instructions to engineers of timber tests. By W.K.

Hatt, 1906, pp. 55. Revised edition, 1909, pp. 56.

Cir. 39--Experiments on the strength of treated timber. By W.K.

Hatt, 1906, pp. 31. Revised edition, 1908.

Bul. 70--Effect of moisture upon the strength and stiffness of

wood. By H.D. Tiemann, 1906, pp. 144.

Cir. 46--Holding force of railroad spikes in wooden ties. By

W.K. Hatt, 1906, pp. 7.

Cir. 47--Strength of packing boxes of various woods. By W.K.

Hatt, 1906, pp. 7.

Cir. 108--The strength of wood as influenced by moisture. By

H.D. Tiemann, 1907, pp. 42.

Cir. 115--Second progress report on the strength of structural

timber. By W.K. Hatt, 1907, pp. 39.

Cir. 142--Tests of vehicle and implement woods. By H.B. Holroyd

and H.S. Betts, 1908, pp. 29.

Cir. 146--Experiments with railway cross-ties. By H.B. Eastman,

1908, pp. 32.

Cir. 179--Utilization of California eucalypts. By H.S. Betts and

C. Stowell Smith, 1910, pp. 30.

Bul. 75--California tanbark oak. Part II, Utilization of the

wood of tanbark oak, by H.S. Betts, 1911, pp. 24-32.

Bul. 88--Properties and uses of Douglas fir. By McGarvey Cline

and J.B. Knapp, 1911, pp. 75.

Cir. 189--Strength values for structural timbers. By McGarvey

Cline, 1912, pp. 8.

Cir. 193--Mechanical properties of redwood. By A.L. Heim, 1912,

pp. 32.

Bul. 108--Tests of structural timbers. By McGarvey Cline and

A.L. Heim, 1912, pp. 1231.

Bul. 112--Fire-killed Douglas fir: a study of its rate of

deterioration, usability, and strength. By J.B. Knapp, 1912, pp.

18.

Bul. 115--Mechanical properties of western hemlock. By O.P.M.

Goss, 1913, pp. 45.

Bul. 122--Mechanical properties of western larch. By O.P.M.

Goss, 1913, pp. 45.

Cir. 213--Mechanical properties of woods grown in the United

States. 1913, pp. 4.

Cir. 214--Tests of packing boxes of various forms. By John A.

Newlin, 1913, pp. 23.

Review Forest Service Investigations. 1913. [Outline of

investigations.] Vol. I, pp. 17-21. A microscopic study of the

mechanical failure of wood, by Warren D. Brush. Vol. II, pp.

33-38.

Bul. 67, U.S.D.A.--Tests of Rocky Mountain woods for telephone

poles. By Norman deW. Betts and A.L. Heim, 1914, pp. 28.

Bul. 77, U.S.D.A.--Rocky Mountain mine timbers. By Norman deW.

Betts, 1914, pp. 34.

Bul. 86, U.S.D.A.--Tests of wooden barrels. By J.A. Newlin,

1914, pp. 12.

REPORTS OF TESTS ON THE STRENGTH OF STRUCTURAL MATERIAL, MADE AT

THE WATERTOWN ARSENAL, MASS.

House Ex. Doc. No. 12, 47th Cong., 1st sess., 1882. Strength of

wood grown on the Pacific slope, pp. 19-93.

Senate Ex. Doc. No. 1, 47th Cong., 2d sess., 1883. Resistance of

white and yellow pines to forces of compression in the direction

of the fibers, as used for columns, or posts, pp. 239-395.

Senate Ex. Doc. No. 5, 48th Cong., 1st sess., 1884. Tests of

California laurel wood by compression, indentation, shearing,

transverse tension, pp. 223-236. Tests of North American woods

(under supervision of Prof. C.S. Sargent in charge of the

forestry division of the Tenth Census), with 16 photographs of

fractures of American woods, pp. 237-347.

Senate Ex. Doc. No. 35, 49th Cong., 1st sess., 1885. Adhesion of

nails, spikes, and screws in various woods. Experiments on the

resistance of cut nails, wire nails (steel), wood screws, lag

screws in white pine, yellow pine, chestnut, white oak, and

laurel, pp. 448-471.

House Ex. Doc. No. 14, 51st Cong., 1st sess., 1890. Adhesion of

spikes and bolts in railroad ties, pp. 595-617.

House Ex. Doc. No. 161, 52d Cong., 1st sess., 1892. Adhesion of

nails in wood, pp. 744-745.

House Ex. Doc. No. 92, 53d Cong., 3d sess., 1895.

Woods--compression tests (endwise compression), pp. 471-476.

House Doc. No. 54, 54th Cong., 1st sess., 1896. Compression

tests on Douglas fir wood, pp. 536-563. Expansion and

contraction of oak and pine wood, pp. 567-574.

House Doc. No. 164, 55th Cong., 2d sess., 1898. Compression

tests of timber posts, pp. 405-411. New posts of yellow pine and

spruce, pp. 413-450; Old yellow pine posts from Boston Fire

Brick Co. building, No. 394 Federal St., Boston, Mass., pp.

451-473.

House Doc. No. 143, 55th Cong., 3d sess., 1899. Fire-proofed

wood (endwise and transverse tests), pp. 676-681.

House Doc. No. 190, 56th Cong., 2d sess., 1901. Cypress wood for

United States Engineer Corps; compression and transverse tests,

pp. 1121-1126. Old white pine and red oak from roof trusses of

Old South Church, Boston, Mass., pp. 1127-1130. Compression of

rubber, balata, and wood buffers, pp. 1149-1158.

House Doc. No. 335, 57th Cong., 2d sess., 1903. Douglas fir and

white oak woods. Transverse and shearing tests; also

observations on heat conductivity of sticks over wood fires and

a stick exposed to low temperature. Expansion crosswise the

grain of wood after submersion, pp. 519-561. Adhesion of lag

screws and bolts in wood, pp. 563-578.

The Mechanical Properties of Wood Including a Discussion of the Factors Affecting the Mechanical Properties, and Methods of Timber Testing · 第 4 / 4 章

Lower bolt, 2, 3, 6, 7, 10, } Air-dried