r. -i of Paecinorri and Peri aj*f as exact as it was p«->ssil>lf ro make them without 



the ap,.^. .... .. . me katheiometer. These authors, however, also negleitf-.l to e»jasi<ler the part 



of the tree fii:>m which the experimental yiieces were taken an»l the degree of seasooing at the time 

 o; at. It is fci: - is not t" - " - ' the tree and changes 



cc_- :y with the a: -" "L thi< i> --^ -nch small .sticks as 



the authors used: so that the result of these experiments are not entirely capaWe of comparison or 

 gener' 



E. - the results of investigations obtained in this field up to the middle of our century, 

 we find that great projrress was made in the methods and the exactness <>f the reasoning, but the 

 results were often contradic* — - ' Tmsatisfiictory. Keco^mizing this, two French .scientists, one 

 a forester, the other a te. . -". <:HEVA:rDiEK and Weetheth. undertook a far-reaching 

 inTestigation- The timlwrs tor experiment were taken from a Lx-ality of the Western Vosges 

 Hoontaias. France, the l<x--al con<iitions of which were thoroughly known t<» the experimenters. 

 In a forest comx'rising ab«>nt lO.WM) acres sufficiently numerous variations of site and kinds of 

 trniber were found. The same exa«rtitude was u.-*ed in the - repa- 

 ration of the test pieces as in the experiments them.-ielve;-. ; . - . r iis of 



satis&«tt«y quality were at their disposal Chevandier and Wertheim published their work, the 

 fruit of m - 1 l»een e ' mh a de, ' i never before 



attained. U- . - - - , . entitleii ■ -« sur la ^ . .ue du bois. 



Tke foDowing questions were to be determined by the authors : 



(1 _-'---; 



chaai^- -- ,, '- — *^ 



i2i Do the me^-hani. i' !.rnT,..rTie8 of tlie wood vary — 



(s) with th« . t. <r„ acconiiQg to the poettioa in the tre« in reistioB to the p^xnts of the eompads ; 



( h ) wtth tht .^-j _ . • ■ . inaistmc ; 



(e) with the position in the tree in relatiaa to the distance irtxa the axis to the circi(BleieBC« at the same 



height: 

 {i) with the poiHtioa in the tree aeeordin^ to the height from the groond' 

 (3) In "" " a do the Dietfha.nical prop^rrie? ' -tajid in the direction ..i riirr ni^er aku-i lu tnc tiirec- 



ti«n p^T^E'- ■ _e sajme respe^tiTely at varyxD _: , -''imihe ;^i.timdf 



;■ trews exert ? 



: mnnal rings ( rate of 2r'»»H!V tfe^* <'it'*«»tt<». »Bd tfc»» ««Q '«»!iditions show J 

 (6 ijctwcTrn tile several meihaiii ' 



(7 > cau be considered proper to .- iml what i-on- 



cloKoaA Tesoit tiieretrooi Sue the praetiee i 



The results of the "r:; -ats of these two - ng to ti: " ' - ' " '^hich we 



employ t-ven tiMiay. T. :s tirst review th^ ..ese iuvr-- . -. ._ ^ we have 



here given, re«i>rdnig in a table the results of exjieriments by their preileeessors. and in eighteen 

 additional" ' ' -':e resnlts of their own work. Here for the first time we find a rather fiill 

 re<rord of - .- nnd nature of the test material Regard is taken of th»* moLsturt- per cent 



in fiooT sta.g»-> ag: fresh, partly tlried. well sea.soneii. and kiln -dry. These authors also 



T^-r.-.] larger I _ ■.^, :>> 'J6 feet in length). They also employe«l the metho«l by sound vibrations 

 -rminetheroetficient of elasticity, and finally correlateil theirresults with a \iew to answering 



T . with<xit doubt, must be considered the fathers of the new science of Timber 



Phyaes, and while their eonclnsions may not be acirepted as having settled ail the questions, 

 b*- ' ' '■ ' .' ilata of record. •■ :tetl out the nxnl along which we 



ij. -.it. Yet it has re ., y untraveled Until our time. 



TwelTe years after Chevandier & Wertheim's publicati^jn there appeared in Germany the most 

 eompr ' ■- ~ -t in thi* line of inv^ - . - . .- fullest dist-u.-^sion of all the 



tn<jw. : ta<rts regarding w<j.». ution. by Dr. H. yr.EDLXSGEii. 



Ij«)fess<jr of forestry and Oberforster at Mohenbeim. Wiirtemberg. The means for his long- 

 , ..nririxK.^ exj)^^"' '-^^- and accumulation of data were furnished by the direction of the Forest 

 mv at If I an<l the Minister of Finuufe of his State. The first fruit of his studies 

 1 the standard work eutitleil The Technical Properties of Timber, for 

 i .- -_ lechnolotcL^t.s. and ilunulacturers. 



