| 21. | Water--Purification--Filtration (2) |
| 22. | Waterworks (14) |
| 23. | Watson, John (1) |
| 24. | Weapons (1) |
| 25. | Weather forecasting (1) |
| 26. | Wedding costume (1) |
| 27. | Weddings (9) |
| 28. | Weissenburg, Battle of, 1870 (1) |
| 29. | Welland (Ont.) (2) |
| 30. | Westminster (London, England) (1) |
| 31. | Westover, Asa (1) |
| 32. | Westphalia (Germany) (1) |
| 33. | Westville (N.S.) (1) |
| 34. | Wharves (4) |
| 35. | White-water canoeing (1) |
| 36. | Widows (1) |
| 37. | Wiesbaden (Germany) (1) |
| 38. | Wigwams (1) |
| 39. | Wildlife conservation (1) |
| 40. | Wilkes, Henry, 1805-1886 (1) |