Страница - 130- p. 15. boars has been changed to bars.
Misaligned typeface has half duplicated the first letter of each line on this page. - p. 26. Both trapboard and trap board have been used in the text
and have been left as printed.
- p. 35. cyiinder has been changed to cylinder.
- p. 65. 2 4 6 8 13 12
changed to
2 4 6 8 10 12. - p. 134. coarses has been changed to coarser.
- p. 132. fig. 3 has been changed to Fig. 3 as used in all other cases.
- p. 141. cyclinder has been changed to cylinder
- p. 208. tightly paced should probably read spaced or placed, but has been left as printed.