Excerpt from A Textbook on Plumbing, Heating, and Ventilation: Principles of Heating and Ventilation, Steam Heating, Hot-Water Heating, Furnace Heating, Ventilation of Buildings, With Practical Questions and Examples In graduating a Centigrade thermometer, the freezing point is marked or zero, and the boiling point the distance between the freezing and boiling points is divided into 100 equal parts; these equal divisions are carried as far below the freezing point and above the boiling point as desired. The reason that Fahrenheit placed the zero point on his thermometer 32 Degrees below freezing was because that was the lowest temperature he could obtain, and he supposed that it was impossible to obtain a lower one. Where there is any doubt as to the thermometer used, the first letter of the name is placed after the degree of temperature. For example, 183 Degrees F. Means 183 Degrees above zero on the Fahrenheit instrument. 183 Degrees C. Would mean 183 Degrees above zero on the Centigrade instrument. 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.