4 DEPARTMENT OF AGRICULTURE BULS. 551-575. 



Department Bulletin* Xo. 555. — Standard Forms for Specifications, 



Tests, Reports, axd Methods of Sampling for Road Materlals: Page. 



Introduction 1 



Recommended standard forms of specifications for materials 5 



Recommended standard methods of testing materials 30 



Recommended standard forms for reporting test results 38 



Recommended standard methods of sampling 45 



Index. 53 



Department Bulletin Xo. 556.- — Mechanical Properties of Woods Grown 

 in the United States: 



Purpose of the study 1 



Scope and method of experiments 3 



Precautions to be used in the use of the data. 4 



Data on green timber 7 



Data on air-dry timber 7 



Explanation of tables 1 and 2 7 



Explanation of table 3 18 



Glossary 20 



Formulae used in computing 24 



Table 1 26 



Table 2 37 



List of publications and papers dealing with the mechanical properties of 



timber 46 



Department Bulletin: Xo. 557. — A Comparison of Several Classes of 

 American Wheats and a Consideration of Some Factors Influencing 

 Quality: 



Introduction 1 



Factors of importance in determining the qualities of wheat. 2 



Milling yield and flour color 2 



Flours of high and of low strength '. 3 



Loaf volume and texture 3 



Water absorption 5 



Classes of wheat studied 5 



Milling vield and related factors 6 



Yield of flour 6 



Yield of bran and shorts 7 



Moisture content and flour yields 7 



Flour yield and weight per thousand kernels 9 



Flour yield and weight per bushel 10 



Color of flour and bread 14 



Relation of yield and color to test weight and soundness 15 



Inseparable foreign material, flour yield, and color of bread 17 



Flour strength 18 



Comparisons of loaf volume 18 



Comparisons of texture 21 



Relation between crude protein in wheat and the strength of flour 22 



Protein content of wheat and flour 24 



Water absorption of flour 25 



Summary 25 



Department Bulletin Xo. 558. — Marketing Grain at Country Points: 



Introduction 1 



Function of the country elevator 2 



Methods of purchase 6 



Methods of sale 11 



Place of sale 12 



Price paid to the producer 16 



Transient and permanent ' ' scoop-shovelers " 21 



Contracting with farmers for future delivery 23 



Storing gra4n for farmers 25 



Farm storage 27 



Handling grain for farmers 29 



Advantage of growing uniform varieties 30 



Farm and elevator scales 31 



Supply of elevators 33 



Cost of operating a country elevator 34 



