LIST OF FIGURES
| A sub-surface irrigation sewage-disposal plant | Frontispiece | |
| FIGURE | PAGE | |
|---|---|---|
| 1. | Plan of settling tank | 15 |
| 2. | Longitudinal section of settling tank | 17 |
| 3. | Sketch of settling tank with longitudinal partition wall | 19 |
| 4. | Forms used for building side walls for concrete tank | 23 |
| 5. | View of settling tank, showing baffles, sludge pipe, drain pipe, and inlet and outlet pipes | 26 |
| 6. | Section showing tank with concrete roof and form for constructing roof | 28 |
| 7. | Form for manhole opening | 30 |
| 8. | Plan and longitudinal section of modified Imhoff tank | 33 |
| 9. | Vertical cross-section of modified Imhoff tank | 34 |
| 10. | Sludge valve for floor of tank | 38 |
| 11. | Sludge valve for side wall of tank | 39 |
| 12. | Sluice gate valve made by Coffin Valve Co | 40 |
| 13. | Ordinary gate valve | 40 |
| 14. | English slide valve with wedge-lock handle | 41 |
| 15. | Flap valve attached to length of sewer pipe | 42 |
| 16. | Flap valve with metallic seat attached | 43 |
| 17. | Flap valve with loose-link hinges | 44 |
| 18. | Intermittent dosing apparatus made by Ansonia Manufacturing Co. | 45 |
| 19. | Simplest form of automatic siphon | 46 |
| 20. | Van Vranken automatic siphon | 47 |
| 21. | Miller automatic siphon | 48 |
| 22. | Double alternating siphons of the “Merritt” type | 49 |
| 23. | Triple alternating siphons of the Miller type | 50 |
| 24. | Single “Merritt” automatic siphon | 51 |
| 25. | Air-lock siphon for admitting and releasing sewage from each one of four beds in regular order | 52 |
| 26. | Plan and section of sub-surface irrigation system | 61 |
| 27. | Plan and section of a portion of a sub-surface irrigation system | 62 |
| 28. | Y-branch of vitrified tile pipe | 64 |
| 29. | Eighth bend of vitrified tile pipe | 64 |
| 30. | Sub-surface tiling | 65 |
| 31. | Photograph of tile laid as if for sewage disposal | 66 |
| 32. | Sub-surface tiling with broken stone or gravel surrounding pipe | 67 |
| 33. | Sub-surface systems on irregular ground | 68 |
| 34. | Special casting of double Y-branch with swinging gate | 69 |
| 35. | Double Y-branch with valves on branches of main carrier | 70 |
| 36. | Sub-surface tiling system with underdrains | 71 |
| 37. | View of sand-filter beds for village in Massachusetts | 75 |
| 38. | Layout for intermittent sand filtration | 78 |
| 39. | Intermittent sand-filtration beds | 79 |
| 40. | Portion of distributing troughs for sand filters | 80 |
| 41. | General view of disposal plant at Bedford Reformatory | 81 |
| 42. | View of sand filter with distribution trough. Settling tank is at the end of the bed | 82 |
| 43. | View of diverting manhole | 83 |
| 44. | Plan of diverting manhole | 84 |
| 45. | Five-way diverting manhole | 85 |
| 46. | General plans of contact-bed system near Albany, N. Y., opposite page | 89 |
| 47. | View of sprinkling filter at Dansville, Pa., in winter | 95 |
| 48. | Distribution of sewage and arrangement of check levees on a hillside | 106 |
| 49. | Distribution of sewage on a hillside of moderate slope | 107 |
| 50. | Square beds for orchards according to some Western practice | 108 |
| 51. | Grain-field in spring in process of irrigation | 109 |
PRACTICAL METHODS OF
SEWAGE DISPOSAL
FOR
RESIDENCES, HOTELS AND INSTITUTIONS