Excerpt from The Journal of the Franklin Institute, Vol. 106: Devoted to Science and Mechanic Arts; July to December, 1878 There is a clear annular space of about 3 cm. Between the flask, which is in the centre, and the inside of this sheathing, and through which the gas flames can circulate. This arrangement allows the flask to heat very evenly; and when the temperature is high enough to cause chemical reaction, has the Special advantage of retaining this heat a long time without great variation. 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.