118 



TABLE OF CONTENTS CONTINUED. 



Page. 



Construction of concrete linings by means of forms. . . 36 



Joints 38 



Expansion joints 38 



Method used near Kelowna by Kelowna Irrigation 



Company 39 



Construction of concrete lining without forms 39 



Cost of concrete linings 41 



Cost of lining without forms 43 



Economy of concrete linings 43 



Steel Flumes 44 



Plain Concrete Pipe Not Reinforced 45 



1. Manufacturing hand tamped cement pipes 47 



Mixtures used 47 



Mixing materials 47 



Process of moulding 47 



Curing the pipe 48 



Coating the pipe 48 



Cost of moulds 48 



Dimensions of cement pipes and rate of manufacturing. . 48 



Cost of making pipe 49 



2. Construction and laying of pipe line 49 



Excavation of trench 49 



Laying the pipe 50 



3. Other methods of making cement pipe 52 



Machine tamped pipe 52 



Pipe made by wet process 52 



Reinforced Concrete Pipe 52 



1. Method of casting reinforced concrete pipe 53 



(Umatilla project, Oregon.) 



2. Method of joining 54 



Bell and spigot joint 54 



Collar joint 54 



Lock joint 54 



3. Method of making and laying reinforced concrete pipe on 



Roswell project, Idaho 54 



4. Cost of making reinforced concrete pipe 55 



5. Advantages and economy of reinforced concrete pipe 56 



IV. DUTY OF WATER AND FACTORS INFLUENCING THE CORRECT USE 

 OF WATER IN IRRIGATION: 



Duty of Water 57 



1. Principal factors affecting the net duty of water 58 



2. Duty of water for orchards 60 



3. Duty of water for alfalfa 62 



4. Duty of water for potatoes 62 



Factors Influencing the Correct Use of Water in Irrigation 63 



1. Disposal of water applied to the soil 63 



2. Relation of soil moisture to soil texture 63 



Percentage of free moisture in soil for plant growth 64 



3. Evaporation of soil water and methods of checking it 65 



Extent of evaporation from bare soils not cultivated 67 



Effect of soil mulches on soil evaporation 68 



Effect of depth of furrows on soil evaporation 68 



4. Percolation of water applied to the soil 68 



Effect of texture of soil and subsoil 68 



Percolation, of water applied in furrows 69 



V. IRRIGATION AND CULTIVATION OF ORCHARDS: 



Distribution of Water 72 



1. Earthen head ditch 73 



