6 DEPARTMENT OP AGRICULTURE BULS. 301-325. 



Department Bulletin No. 314. — Methods for the Examination of Bitu- 

 minous Road Materials: Page. 



Classification of materials 2 



Scheme of examination 2 



Specific gravity determination 4 



Specific viscosity determination 7 



Float test 9 



Penetration test 11 



Melting point determination 14 



Flash and burning points 16 



Volatilization test 19 



Distillation test 21 



Dimethyl sulphate test 25 



Bitumen soluble in carbon disulphide 25 



Bitumen insoluble in paraffin naphtha 28 



Bitumen insoluble in carbon tetrachloride 30 



Fixed carbon 30 



Paraffin scale 32 



Extraction of bituminous aggregates 35 



Grading the mineral aggregates 38 



Voids in the mineral aggregate 39 



Bituminous emulsions 41 



Appendix 43 



Laboratory equipment 43 



Forms for reporting tests 47 



Department Bulletin No. 315.' — Cantaloupe Marketing in the Larger 

 CrriES, with Car-lot Supply, 1914: 



Introduction 1 



Extent of investigations 1 



Systems of distribution within cities 2 



Factors which influence prices 3 



Some trade factors influencing the marketing of cantaloupes 11 



Cantaloupe shipments in 1914 15 



Publications of U. S. Department of Agriculture relating to marketing of 



farm products 20 



Department Bulletin No. 316. — Willows: Their Growth, Use, and 

 Importance: 



Introduction 1 



The tree and its forms 2 



Soil, moisture, and light 7 



Susceptibility to injury 7 



Life history of the black willow 9 



Characteristics of willow wood 26 



Uses of willow wood 27 



Uses of willows for protection 37 



Planting willows 43 



Cultivation and care 48 



Cutting 48 



Cost of growing willows 49 



Yield from willow plantations 50 



Department Bulletin No. 317. — Larch Mistletoe: Some Economic Con- 

 siderations of Its Injurious Effects: 



Introduction 1 



The larch mistletoe 3 



The forest 3 



Physical and climatic features of the forest region 5 



Fungous enemies of the larch 11 



The effects of mistletoe on its host 12 



Effect of mistletoe burls on the merchantability of larch trees 22 



Method of control 23 



Conclusions 24 



Publications of U. S. Department of Agriculture relating to forest tree 



disease 27 



