CONTENTS, 



Page. 



Need of thk ixvesticatk >x 1 



Prevailing ij^iiorniirc oftho siil).jeit 1 



Conseiiucnt waste of valiiiiblti iiiati'i'ial 1; -' 



PreHeut ciigiiieering tables nuieliable, based on European woods and on few and small test pieces 2, 3 



Eelatiou of the iiivestigatio)i to forestry ^ 



Comprehensiveness of proposed investigation - 3 



Letters from engineers, scientific societies, and others, expressing interest in the investigations and urging 



their eontinnanee 4-16 



Scope and historicai. development of the science of " Timber Physics " 17-28 



American work in timber physics ^ 26-28 



OlUJANIZATION AND METHODS OF THE TIMUEK EXAMINATIONS IN DIVISION OF FORESTRY 29-57 



Work at the test laboratory 31 



Examination into tlie jihysieal properties of test material 42 



Instructions for the collection of test pieces ior timber investigation 51 



Records : 



Forms for collectors 5*4 



Sample records of lests 55, 56 



Records of physical examinations 57 



CukSSLFIED INDEX ' 



ILLUSTRATIONS AND PLATES. 



Figures 1-4. Method of sawing test sticks 31 



5. Standardizing tests with calibrating springs 33 



-. Curve of cross-bending test 36 



6. Relation between cross-breaking strength and modulus of elasticity 39 



7. Relation Ijetweon compressive strength and specific gravity 39 



S. Variation of compressive strength and sjiecitic gravity for varying percentage of moisture 41 



9. Relation between cross-breaking strength and percentage of moisture 41 



10. Apparatus for determining specific gravity 44 



— . Method of splitting disks for physical examinations 53 



— . Curves of cross-breaking tests 55, 56 



11. Diagram representing results of physical examinations 57 



Plate 1. Floor plan of test laboratory at St. Louis. 



II. Plan of large beam-testing machine. 



III. Plan of small beam-testing machine. 



IV. Plan of universal (Richie " Harvard") testing machine. 

 V. Illustration of tension and shearing tests. 



VI. Plan of column-testing machine. 



II 



