TIMBER PHYSICS — STRENGTH OF SPECIES. 



363 



were available, comprises so far 32 species with 308 test trees, furnishing over 6,000 test pieces, supplying material 

 for 45,336 tests in all, of which 16,767 were moisture and specific gravity determinations on the test material. 



In addition to the material for mechanical tests, about 20,000 pieces have been collected from 780 trees (including 

 the 308 trees used in mechanical tests) for physical examination to determine structure, character of growth, specific 

 gravity of green and dry wood, shrinkage, moisture conditions, and other properties and behavior. 



In addition to the regular series of tests, the results of which are recorded in the subjoined tables, special 

 series, to determine certain questions were planned and carried out in part or to finish, adding 4,325 tests to the 

 above number. 



Account of test material. 



No. 



Name of species. 



Num- 

 ber of 



trees. 



Number 

 of me- 

 chanical 



tests. 



Average 



specific 



gravity 



of dry 



wood. 



Localities and number of trees from each. 



1 



Longleaf pine ... . » 



68 



12 



22 



32 



17 



8 



4 



20 



4 



6,478 



2, 113 



1,831 



3,335 

 540 

 412 

 690 



3,396 

 354 

 225 



1,009 

 911 

 256 

 935 



479 



222 



132 



649 



1,035 



794 



300 



197 



100 



294 



172 



84 



91 



201 



476 



45 



508 



0.61 



.63 



.51 

 .53 



.38 

 .50 



.46 

 .37 

 .51 

 .80 

 .74 

 .80 

 .74 

 .73 

 .73 

 .72 

 .73 

 .72 

 .73 

 .81 

 .85 

 .73 

 .77 

 .78 

 .78 

 .89 

 .54 

 .74 

 .62 

 .62 

 .59 



Alabama, coast plain (22) a; uplands (6) ; hill district (6) ; Georgia, undulat- 

 ing uplands (0) ; South Carolina, coast plain (7) ; Mississippi, low coast 

 plain (2) , Louisiana, low coast plain, gravelly soil (7) ; sandy loam (6) j 

 Texas, low coast plain (6). 



Alabama, coast plain (6); Georgia, uplands (1); South Carolina, coast (5). 



Alabama, uplands (4); Missouri, low hilly uplands (6); Arkansas, low hilly 



uplands (6) ; Texas, uplands (6). 

 Alabama, mountainous plateau (8) , low coast plain (6); Arkansas, level flood 



plain (5) ; Georgia, level coast plain <6) j South Carolina, low coast plain (7). 

 Wisconsin, clay uplands (5) , sandy soils (4) ; sandy loam (5) ; Michigan, level 



drift lands (3). 

 Wisconsin, drift (5) ; Michigan (3). 



Alabama, low coast plain. 



South Carolina, pine barren (6) ; river bottom (4) ; Louisiana, coast plain, 



border of lake (4) ; Mississippi, Yazoo bottom (3) ; upland (3). 

 Mississippi, low plain. 



(From lumber yard.) 



Alabama, ridges of Tennessee Valley (5) ; Mississippi, low plain (7). 



Mississippi, low plain (7) ; Arkansas, Mississippi bottoms (3). 



Alabama, Tennessee Yalley (5) ; Arkansas, Mississippi bottom (3). 



Alabama, Tennessee Yalley (4) ; Arkansas, Mississippi bottoms (3) ; Missis- 

 sippi, low plain (4). 

 Alabama, Tennessee Yalley (5); Arkansas, Mississippi bottom (2).& / 



Arkansas, Mississippi bottom. 



Alabama, Tennessee Yalley (5). 



Mississippi, low plain (4). 



Alabama, Tennessee Yalley (5) ; Arkansas, Mississippi bottom (3) ; Missis- 

 sippi, low plain (4). 



Alabama, Tennessee Yalley (5) ; Arkansas, Mississippi bottom (3) • Missis- 

 sippi, low plain (3). 



Mississippi, alluvial plain (3); limestone (3). 



Mississippi, low plain. 

 Do. 



9 



(Pmus palustris.) 



3 



(Pinus heterophylla.) 

 Shortleaf pine 



4 



(Pinus echinata.) 

 Loblolly pine -. ... 



5 



(Pinus tceda.) 

 White pine........... ........ 



6 



7 



(Pinus atrobus.) 



(Pinus reainosa.) 

 Spruce pine .......... 



8 



(Pinus glabra.) 



q 



(Taxodium distichuni.) 



10 



(ChamaBeyparis thyoides.) 



11 



(Pseudotsuga taxifolia.) 



12 

 10 

 8 

 11 

 7 

 3 

 5 

 4 

 12 

 11 

 6 

 4 

 2 

 4 

 3 

 2 

 3 

 2 

 3 

 3 

 1 

 7 



19, 



(Quercus alba.) 



13 



(Quercus lyrata.) 



14 



(Quercus minor.) 



15 



(Quercus michauxii.) 

 lied oak 



16 



17 



(Quercus rubra.) 

 (Quercus texana.) 



18 



(Quercus velutina.) 



19 



(Quercus nigra.; 



90 



(Quercus pbollos.) 



21 



(Quercus digitata.) 



22 



(Hieoria ovata!) 



23 



(Hicoria alba.) 



24 



(Hieoria aquatica.) 

 Bitternut hickory. - - - - - 



Do. 



25 



(Hicoria minima.) 



Do. 



26 



(Hicoria myristicaBformis ) 

 Pecan hickory 



Do. 



9,7 



(Hicoria pecan.) 



Do. 



28 



(Hicoria glabra.) 



Mississippi, bottom. 

 Arkansas, bottom. 



29 



(Ulmus americana.) 



30 



(Ulinus crassifolia.) 



Mississippi, bottom. 

 Do. 



31 



(Fraxinus americana.) 



32 



(Fraxinus lanceolata.) 



Arkansas, bottom (3); Mississippi, low plain (4). 





(Liquidambar styraeifl.ua.) 





a Sixteen of these were bled trees to study the effects of boxing. 



& These two should probably be classed as Southern red oak. They were collected before the distinction was finally decided upon. 



Note The values for specific gravity here given refer to "dry'' wood of test material— i. e. t wood containing variable amounts of 



moisture below 15 per cent; the moisture effect has therefore not been taken into account, but more careful experiments indicate that its 

 nfluence on specific gravity at such low per cent is so small that it may be neglected for practical purposes. 



As will be observed, some species, notably tbe Southern pines, have been more fully investigated, and the results 

 on these (which have been published more in detail in Circular No. 12) may be taken as authoritative. With those 

 species of which only a small number of trees have been tested this can be claimed only within limits and in 

 proportion to the number of tests. 



