Excerpt from Practical Handbook on Direct-Acting Pumping Engine and Steam Pump Construction Direct-acting pumps for dip workings in collieries and mines are best worked by compressed air; it dispenses with the hot steam pipes and exhaust steam, and improves the ventilation in the workings by the cool exhaust air. When worked by steam a condenser ought to be used: either an injection condenser fixed behind the pump cylinder, having an air pump actuated by a prolongation of the pump rod; or a suction condenser, by means Of which the exhaust steam is sucked out of the steam cylinder by the suction of the pump and condensed by the suction water before entering the pump. In dip workings it is very advantageous to use a lot of small pumps, instead of one large one, for in dry seasons one or two of them can be worked whilst the others are standing, therefore no more steam is used than actually necessary; and in case of one breaking down, the other pumps can be worked to keep the water down during repairs. 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.