Johnson's New Universal Cyclopædia, Vol. 1

Angebote / Angebote:

Excerpt from Johnson's New Universal Cyclopædia, Vol. 1: A Scientific and Popular Treasury of Useful Knowledge, Part II. Cavalry-EzraIn consequence of their peculiar properties, the hydraulic limes cannot be kept on hand in a state of paste, like com mon lime. They are preserved in casks or sacks in the condition of powder, and in using them for mortar or con crete, especially those that are eminently hydraulic, it is not well to mix more than one day's supply in advance. The lime and the sand may be mixed together dry, and kept on hand a long time in that condition if protected from the weather, but the water should not be added until a few hours before the material is to be used, whether for mortar or concrete.The method usually pursued in manufacturing hydraulic limes is as follows: The stone, after being quarried and broken up into pieces not exceeding generally twelve or fifteen pounds in weight, is burnt in any suitable kiln at a heat just sufficient to expel the carbonic acid, and then, after being drawn from the kiln and while still warm, is sprinkled with from 15 to 20 per cent. Of its own weight of water. The slaking soon begins, and the stone falls to pieces, some of it in fine powder, and the rest in unslaked lumps of various sizes. The mass is then thrown together in large heaps, where it remains undisturbed for six or eight days, in order that the slaking may be completed by the steam evolved. It is then screened through fine wire cloth to get rid of the unslaked lumps, packed in sacks or barrels, and sent to market.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis 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.