ILLUSTRATIONS. 7 
Page. 
16. Plan of drifting operations on Solomon Hill, Klondike 85 
17. Details of steam point and erosshead 90 
18. Dawson self-dumping carrier 94 
19. Map of portion of Juneau district, Alaska 114 
20. Section of ditch in construction 122 
21. Map of Miocene ditch 124 
22. Method of nesting made-up hydraulic pipe for shipment 129 
23. Various forms of pipe fittings 131 
24. Device for reenforcing joints of pipe 132 
25. Device for setting pipe by battering 132 
26. Pipe wrench for setting and unsetting hydraulic pipe 133 
27. Bracing hydraulic pipe on steep slope , 133 
28. Method of bracing giant 136 
29. Method of hydraulicking frozen gravel, Klondike benches 137 
30. Sluice box used on McKee Creek, Atlin, British Columbia 143 
31. Tightener used in making sluice boxes, Atlin, British Columbia 146 
32. Rail riffle used in Seward Peninsula 149 
33. Hood in head box of tail sluice 153 
34. Angles for upper tumbier 179 
35. Tailings well stacked 183 
36. Tailings poorly stacked 183 
37. Spud digging 185 
38. Spud digging 186 
39. Spud digging 187 
40. Mud box 192 
41. Modified Caribou undercurrent 194 
42. Improved Hungarian riffle used at Oroville 195 
43. " Kulibinka ' ' sluice and undercurrent used in Siberia 196 
44. Modified Siberian pan for handling clayey gravel 198 
45. Pole riffle fitted with knives for breaking clay 200 
46. Riffle to hold divided sheet of quicksilver 202 
47. Special block riffle for saving porous gold 202 
48. Iron grate riffle, Seward Peninsula 203 
49. Method of constructing road over frozen muck, Klondike 225 
