Excerpt from The Moulder's and Founder's Pocket Guide: A Treatise on Moulding and Founding in Green-Sand, Dry-Sand, Loam, and Cement; The Moulding of Machine Frames, Mill-Gear, Hollow-Ware, Ornaments, Trinkets, Bells and Statues; Description of Moulds for Iron, Bronze, Brass, and Other Metals Sand is the most common, and certainly the most perfect and convenient material. It is superior to all other materials for moulding. Sand is more or less porous, and very refractory, so that the hot metals do not melt nor bake it; two qualities of great importance in the successful operations of the business. The various kinds of good moulding sand, employed in foundries for casting iron or brass, have been found to be of an almost uniform chemical com position, varying in grain or the aggregate form only. It contains between 93 and 96 parts of silex or grains of sand, and from 3 to 6 parts of clay, and a little oxide of iron, in each 100 parts. Moulding sand which contains lime, magnesia, and other oxides of metal, is not applicable, particularly for the casting of iron or bronze. Such sand is generally too weak or too close; it will not stand, or retain its form. 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.