Excerpt from Equipment and Methods for Measurements of Soil Temperature The bimetal dial thermometersfi/ have a coil-within-coil structure about 1 inches long located in the end of a hollow stem. Changes in temperature cause a rotary action of the bimetal helix; this turns a shaft on which a pointer is mounted. The instruments used in this study employed three indicators. One indicated the current temperature, a second the maximum temperature, and a third the minimum temperature. The thermometers can be purchased with different stem lengths for different soil depths. Van Bavel and Forrest (5) concluded that these thermometers were accurate to less than 1° F., were easy to read, and could withstand normal field exposure. 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.