Work of powder post borers in hickory poles 104 27. Work of powder post borers in hickory poles 104 28. Work of powder post borers in hickory handles 105 29. Work of round-headed borers in white pine staves 111 30. U. S. Forest Service humidity controlled dry kiln 161 31. Section through moist-air dry kiln 189 32. Live steam single pipe heating apparatus 190 33. Live steam double pipe heating apparatus 191 34. Vertical Pipe heating apparatus 193 35. Progressive dry kilns 197 36. Apartment dry kilns 199 37. Pocket dry kilns 201 38. Tower dry kiln 203 39. Box dry kiln 205 40. Edge-wise method of piling 206 41. Edge-wise method of piling 207 42. Automatic lumber stacker 208 43. Automatic lumber stacker 208 44. Battery of three automatic lumber stackers 209 45. Battery of three automatic lumber stackers 209 46. Lumber loaded edge-wise on kiln truck 210 47. The lumber unstacker 211 48. The lumber unstacker car 211 49. Method of piling veneer on edge 212 50. Kiln truck loaded cross-wise of kiln 213 51. Kiln truck loaded cross-wise of kiln 214 52. Kiln truck loaded end-wise of kiln 214 53. Kiln truck loaded end-wise of kiln 215 54. Method of piling staves on kiln truck 216 55. Method of piling staves on kiln truck 216 56. Method of piling tub or pail staves on kiln truck 217 57. Method of piling bundled staves on kiln truck 217 58. Method of piling shingles on kiln truck 218 59. Method of piling shingles on kiln truck 218 60. Method of piling shingles on kiln truck 219 61. Kiln truck designed for loose pail staves 219 62. Kiln truck designed for handling short stock 221 63. Stave bolt truck 221 64. Stave bolt truck 222 65. Stave bolt truck 222 66. Stave bolt truck 223 67.