Excerpt from Illinois' Forests in 1998 Tables in the appendix relating to sawtimber volume are presented in both International 1 4 inch rule and Doyle rule. International 1 4 inch rule is the usda Forest Service standard while Doyle is the common measure used in Illinois by forest industries and land management agencies. Because these results are used nationally and consistent comparisons are crucial, International 1 4 inch rule is used as the unit of measure for sawtimber volume unless Doyle rule is noted in the text. We have made an effort to include Doyle tables and discussion where appropriate to improve the utility of the inventory results for regional and local users of these results. Data from new inventories are often compared with data from earlier invento ries to determine trends in forest resources. However, for the comparisons to be valid, the procedures used in the two inventories must be similar. As a result of our ongoing efforts to improve the efficiency and reliability of the inventory, several changes in procedures and definitions have occurred since the last Illinois inventory in 1985. Because some of these changes will make it inappropriate to directly compare the 1998 data with those published for 1985, data from the 1985 inventory have been reprocessed using the 1998 procedures. Please refer to the section labeled Comparing the fourth inven tory of Illinois with the third inventory in the appendix for more details. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.