TIMBER PHYSICS — METHODS. 



377 



In order to see Iiow far the formula 1 may l>e applicable to beams of the same material the data obtained on the 

 small beams cut from one of the large beams were subjected to scrutiny, basing the calculations on the data from 

 the adjoining compression block. The calculated result compared with the actual breaking load showed a most 

 convincing similarity, as will be apparent from the table herewith presented: 



Strength of small beams, calculated by Neely's formula' from compression strength, on the assumption that the relative 



position of the neutral plane at rupture is the same as found in large beams. 



[Shortleaf pine, large beam No. 13, special series.] 





__ 



Dal 



,a observed in testing. 





1 





Results calculated 



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rupture. 



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Lbs. 



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d 



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1 P* 



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Lbs .per 

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rfr 



d e 



T 



X;i 



Mr 



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Inch. 



Inches. 



Lbs. pe 

 7, 350 



r sq. in. 

 M30 



Lbs. 



Inclies. 



Lbs.jper 

 sq. m. 



Lbs. 



Inches. 



Inch 

 pounds. 



Lbs. 



3. 51 



3.5G 



4,300 



4,708 



3,760 



1.46 



1.23 



10,517 



7,677 



7,719 



0.97 



3.18 



58, 760 



2,200 



0.296 



3 



50 



3.75 



3. 37 



7,910 



4,«10 



5,000 



Sj.JS J V 



4,430 



1.56 



1.31 



10, 979 



8, 564 



8,552 



1.04 



1.26 



66, 380 



2,800 



0.391 



i 



50 



3. 55 



3. 60 



7,790 



1,500 



4,710 



5,057 



3,969 



1.48 



1.24 



10, 885 



8, 055 



8,020 



99 



1.19 



63, 216 



2,400 



0.413 



5 



50 



3.49 



3.50 



8,230 



4,070 



4,080 



4,*203 



4,220 



1.45 



1. 22 



9, 675 



7,014 



7,061 



0.97 



1.17 



52, 535 



2,400 



0.345 



e 



50 



3. 58 



3. 54 



7,750 



4,130 



4,690 



*4 ^ <rP JL 



4,296 



1.49 



1.25 



9,894 



7,371 



7, 376 



0.99 



1.20 



57, 144 



2,600 



0. 356 



7 



50 



3. 53 



3.50 



7,810 



4,100 



4,540 



4,4&0 



Tr» A «J*/ 



1.47 



1. 23 



9,943 



7,308 



7,200 



0.98 



1.18 



55, 248 



2,400 



0.431 



8 



5o 



3.50 



3.54 



7,470 



8,S70 



4,470 



4,578 



*X«j 1 1 c> 



1.48 



1. 25 



9,104 



7,381 



6,840 



0.09 



1.20 



57, 222 



2,500 



440 



a 9 



50 



3.52 



3.54 



5, 130 



3,SSO 



."$,000 



4, tOO 



3,078 



1.47 



1.23 



9,274 



6,810 



6,751 



0.98 



J • 18 



52, 118 



1,800 



0. 328 



10 



50 



3 52 



3.45 



7, 510 



3,080 



4,2S0 



3,854 



3,800 



1.47 



1. 23 



8,796 



6,465 



6,403 



0.98 



1.18 



48, 177 



2,200 



0.387 



11 



50 



3.47 



3. 52 



6, 370 



3,750 



3,600 



*»»«>1(« 



3,893 



1.44 



t.21 



8,926 



6,427 



6, 485 



0.96 



0.87 



41, 400 



2,200 



0.372 



12 



50 



3.48 



3. 54 



6, 580 



3,540 



3,760 



3,007 



3,395 



1.45 



1.22 



8, 415 



6,101 



6,124 



0.97 



1.17 



46, 219 



1,940 



0.300 



a Failed, due to knot. 

 Note.— Columns of figures in ^amo distinctive type to be compared one with the other. 



On the whole, It is in no way boastful to assert that this work has already furnished prac- 

 tical data enough to more than pay the expenses incurred ten times over; that its fruits are not 

 half gathered, and that for more than a quarter of a century its results will serve as a basis for 

 the user of wood and as the guide to the teacher and experimenter. 



Development of the Science of Timber Physics and Methods Employed in the 



Investigation. 



Since the elaborate plan and methods of this study of our woods denotes an entirely new 

 departure in timber investigations, at least in our country, it is only fitting to place the credit for 

 its conception, for the elaboration of the plan, the organization of the work, and the persistent 

 prosecution of the same in spite of many drawbacks and lack of support. This credit belongs to 

 Dr. B. E. Fernow, chief of the Division of Forestry. The plan was first foreshadowed in his second 

 report (1887, p. 37) as chief of that division, and the word "timber physics" was there used for 

 the first time, and the essentials of the future plan were there discussed. In a small tentative 

 manner the first steps to put it in operation were made in 1888. In the report for 1889 we read : 



The investigations into the technology of our timbers and especially into the conditions upon which the qual- 

 ities of our timbers depend—for which Mr. Roth of Ann Arbor has begun preliminary studies— has also made but 

 slow progress for lack of means. 



In the report for 1890 we find, besides an account of the tests on Northern and Southern oaks 

 referred to before, the statement that "by the increase of appropriations the forest technological 

 investigations referred to in former reports have become possible on a scale which was hitherto 

 unattainable," and ^ description of the plans is given, But the first fuller statement of tbe 



