25 



getlier till' experiences wliich had aceiiiiiiilaleil in rin^ nieeiiaiiicai, iihysical, and ciieniieal treatment 

 of woods and in re.siard to 1 heir iJioperlies. 1 lis tollowers, E(ii5i;i; T Uovkk, (lichibneh dec veiyleicli- 

 endeii mechauischen Teehnoh)j;ie, 1878), Franz StObchkn-Kiuciiner (Karniarseh-llecrens tech- 

 nisehes Woerterhneh), (hird edition, lSS(i, and Prof. A. Ledkiuir (Die Vera Hx-itunu- des llol/.es aiif 

 ineelianiseheni Wege, 1.S.S1), could use alieadythe \vorl< of the foresters and Ixitanists, Niirdlinyer, 

 Dr. Julius Wiesuer, Dr. R. Hartig, Theodor Hartij^, etc. A good eouipihitory woik ou the pro[i- 

 ertiesof wood, unieli used and cited in teclniiealcirch's, is IttnoLPii (jOTTGki'heu's I'hysisehe und 

 cheniische IJescliatlenheit der llaunniterialien (IMiysical and Ciieinieal ti>ualities of Building 31ate- 

 rials), third edition, IJerlin, ISSO. 



An entirely modern idea of the part which the properties of wood play in technological regard 

 is presented by Ledebur, who separates them into " working proi)erties" ( Arbeitseigeuschalten ) and 

 "technological })ropertics" ((rewerl)seigenschaften). 



In addition to those, authors who developed timber physics in the mechanical direction, a num- 

 ber of botanists must be mentioned who made a specialty of tlie study of wood in its anatomy, 

 physiology, and histology, with the use of the microscope. 



Dr. JuLirs VViesnkk, of Vienna, gave a new form to this branch of investigations and placed 

 it on a scientific basis. His main works in this field are, Einleituug in die technisclie Microscojjie 

 (Introduction into Technical Microscopy), Vienna, 1807, and Die KohstolVe des PHanzcnreiclis 

 (The raw materials of the Vegetable Kingdom), Leiijzig, JS7.'J. In the latter work for tlie first time 

 in an extensive manner were given the characteristics for the discrjmiinition of the different kinds 

 of wood, their phy~sical jiroperties and their use, and numy current misconceptions were shown up 

 and permanently removed. 



Dr. J. MoELLER, distinguished by his excellent "(Jontributions to the Comparative Anatomy 

 of Wood,'' and by other studies, published in 1883 his vei'y valuable monogra])h, Die Kohstott'e di^s 

 Tischler-nnd Drechsler-Gewerbes, 1 Theil, das Ilolz (Kaw Materials of the Cari)enters' an<l Turners' 

 Industry, part I, Wood), in which were discussed in an ai)t manner botanical as well as technical 

 points. 



The following botanists also furnished various contributions : Boehni, R. and Th. llartig, I loenel, 

 Reinke, Rossmann, linger, Sanio, Schacht, Weiss, Willkomin, and many others. 



Nordlinger, too, enriched the literature, after the appearance of his iimin work, with sjjccial 

 studies, e. (/., Der Holzring als Gruudlage des Baumkorpers (The Annual King as basis of tlie body 

 of the tree), Stuttgart, 1872. R. Haktig investigated green and dry weight, etc., the water con- 

 tents and the shrinkage of pine timber (Berlin, 187-4), and published in 18.S.") the excellent mono- 

 graph Das Holz der deutschen Conifereu (The Wood of the German Conifers). J. Sachs pub- 

 lished his investigation into the Porositiit des Holzes (Porosity ()f Wood), Wiirzburg. 1877, etc. 



In an api^endix will be found in addition a list of works which serve the needs of the practice 

 immediately and the popularization of tlie science, containing many valuable data, besides refer- 

 ences to articles bearing on the sciences of tindjer physics. 



I!y far the greater part of the work has been done by Gernnin investigators, although valuable 

 sporadic additions have been made by Fren(;h, English, and American workers. 



Of Knglish publications which tr(!at broadly on the subject in connection with other mailcis 

 Professoi' Uankink"s .Manuals of CMxil Engineering, of ^Vpplied .Mechanics, and ol -Machinery and 

 Millwork and Trkd(K)Ld's Cari)entry are ])erhai)S best known. 



One of the newest and best publications on the general subject of testing is that of W. C. 

 Unwin, The Testing of Materials of Construction, London, 1888, which besides a general di.scnis- 

 sion on the pro])erties of inatei-ial and of methods and nia<hinery for testing, devotes fourteen 

 l)ages to timber especially, in wliicli Bauschinger's and Professor Lanza's experiments are discussed 

 at lengtli. 



In addition there may be mentioned, besides the references made in the foregoing historical 

 account, Tnos. LAbLETT's Timber and Timber Trees, London, 187;"). Tests on large beams were 

 made by Lystee, engineer in chief of Mersey Docks and Harbor Board, recin-di'd in Engineering, 

 London, volume 10, 1S7."», and by McCi.ii;E, Ct.ark, a7i(I <!raiiam; references to these are fouiul 

 in Burr's Elasticity and Resistance of the Materials of Kngineering. 

 17241— No. (i 1 



