STliKNCTII. <,)! 



Duhamel considered that specific weight is a measure of the 

 strength of wood, and he was followed in this way by other 

 investigators. Hartig* and his pupils went too far in tin's 

 direction, as they aflirmed the identity of heavy = strong, and 

 of light = weak, stating that heavy sprucewood is always 

 stronger than light sprucewood ; they forgot that the most 

 costly and excellent sprucewood, resonant wood, is the lightest 

 wood of this species. Omeis followed Hartig in basing 

 strength on specific weight only, in the case of Scots pine; 

 Kichhorn for oak; Uertog for silver-iir : Schneider for ash. 

 The, best works on the subject are given below. \ 



Tehnajer gives the following data in ions of 1000 kilos per 

 square centimeter of wooden rods, half a meter long: 



It cannot bo affirmed from Tel HIM jer's results that the 

 moduli of strength and elasticity are correspondent. Most 



* It. Hartig, " Untereuchungen Ml KM- die Kiiistelnui.tr und Eigenschaf ten des 

 Kisenhol/es/' " Verachiedenheiten in der Oualitiit u. im anatomischen I'.au 

 der Fichtenhol/e-." Foretlich Nat. /eitun-. IS.L'. IMC?. 1SJM. 



f N'ird linger, " Die Kla>( i/.itiit der Hnl/.er." Xeiifrlhl. f. d. rrs. F.rst \ve-.-u. 

 1SS7 S'.i. I',aushinL r cr. " IClast iciliit u. l-'cst i^kcit. verscliicdener N:i.delliiil/cr." 

 Munich. ]ss;;, ISS7. Sclnvappacli, I'ntcrsiicliiin^-n iiher llaiiin'jcwicli) u. 

 Druckfcsf i_fl<( it des IIol/.-s." ls ( .7. I MIS. I'.iihler. " rntersucliiin L L r en iilter di- 

 Oualitiit des in lichten u. ^ex-hlnssenen Stand erwachscneii Tannen u. l-'ichten 

 hol/.es.'' Landdlt. " I'riit'un.ir der Kesti^kcit u. Klasi i/itiil iler I'.auhill/.er." 

 Schwei/. /eitsehril't, ISSii. Hadeck u. Yanka. " riitersiicliun.tren iiber die 

 Klasti/itiit u. Kesi iirkeit der iisterreich : I'auhillx.er. I. Fichte Siidtirols," I'.M.n. 

 'I'etiuajer. ' Priif ung der schweizerischen laiiln"l/er." l.ss;; IMH;. l-'crndw and 

 Itntli. in several pamphlets on the strength of American \voods. ' Kepitrts 

 on the si relict li <>!' structural timber.'" \\'. K. Halt. 1'nited States of America 

 Forest Service. Circular 11."). Oct. 21, 11)07. 



