xiv LIST OF ILLUSTRATIONS 



FIG. PAGE 



19. An artesian well 43 



20. Three tubes filled with soil and placed with the lower end 



in water for two hours 45 



21. Lamp chimneys filled with soil and placed in water to see 



how fast it will be drawn up by wick action ... 46 



22. New growth on two trees standing near together ... 47 



23. Brick and sponge showing action of mulch .... 48 



24. Dry farming in the state of Washington .... 50 



25. Alfalfa field irrigated by flooding (check irrigation) . . 52 



26. Furrow irrigation, showing deep furrows . . . .52 



27. Diagram showing how far the water soaks down into silt 



and clay 53 



28. Diagram showing how much better the water goes into the 



soil from a broad furrow 54 



29. Testing the soil by means of a " soil probe " ... 55 



30. Ancient Egyptian plow 61 



31. The method of plowing still used in Egypt . . . .61 



32. A breast plow 62 



33. A plow still used in Chile 62 



34. A soil crumb greatly enlarged to show the particles . . 63 



35. A diagram to show the effect of plowing .... 64 



36. Various kinds of plows . .65 



37. Disk plow 66 



38. Several kinds of harrows 68 



39. A branch fitted into a cork which stoppers a bottle of water 75 



40. Blue gum, showing leaves which, by hanging straight down, 



avoid excessive sunlight 77 



41. Branch of geranium 78 



42. Branch of chestnut 78 



43. The reach for light of a tree . . . . . .79 



44. The burning candle, the sprouting seeds, and the frog use 



up the oxygen of the air so that nothing can burn in it . 85 



45. Cambium growing out to heal the wounds at the end of 



grape cuttings ......... 88 



46. Improper cutting of a limb 89 



47. Proper cutting of a limb 89 



48. Cherry blossom cut open to show the parts of the flower . 92 



