AGRICULTURE FOR SOUTHERN SCHOOLS. 29 
Lesson 4. — Construction of Tile Drains. 
1. Ditching methods. 
2. Laying the tile. 
Exercise 2. — Laying Tile. 
See Farmers' Bulletin 638, Exercise 36, Digging Ditch and Laying 
Tile. 
IRRIGATION. 
(2 lessons, 1 exercise.) 
References. — Irrigation in Humid Climate, Farmers' Bulletin 46. Possibilities 
and Need of Supplemental Irrigation in the Humid Regions, Yearbook Separate 570. 
Lesson 1. — Relation of Irrigation to Agriculture. 
1. History of irrigation. 
2. Present status of irrigation farming. 
3. Supplemental irrigation in humid regions. 
Lesson 2. — Practical Irrigation. 
1. Laying out the ditches. 
2. Use of water in irrigation. 
Special references. — The following Farmers' Bulletins: 138, Irrigation in Field and 
Garden; 158, How to Build Small Irrigation Ditches; 263, Practical Information for 
Beginners in Irrigation. 
Exercise. — Preparing Garden for Irrigation. 
See Farmers' Bulletin 638, Exercises 38, 39, and 40, Irrigation. 
TERRACING. 
(2 lessons, 1 exercise.) 
Reference. — The Mangum Terrace in Its Relation to Efficient Farm Management, 
Bureau of Plant Industry Circular 94. 
Lesson 1. — Purposes of Terracing. 
1. Gullying and other forms of erosion. 
2. Contours and terraces in ornamental planting and orchards. 
3. Types of terraces. 
Lesson 2. — Construction of Terraces. 
1. Laying out contour lines. 
2. Use of the A frame and other forms of levels. 
3. Making the terrace. 
Exercise. — Construction and Use of Terrace Level. 
See Farmers' Bulletin 638, Exercise 37, Laying Out and Building a 
Terrace. 
ROADS. 
(3 lessons, 2 exercises.) 
References. — The following Farmers' Bulletins: 311, Sand-clay and Burnt-clay 
Roads; 321, The Use of the Split-log Drag on Earth Roads; 338, Macadam Roads; 
505, Benefits of Improved Roads; 597, The Road Drag and How It Is Used. 
Lesson 1. — Importance of Good Roads. 
1. Relation of farming to roads. 
2. Financial benefit. 
3. Social benefits. 
