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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1900 Excerpt:...were more persistent, the only palliative being to improve the circulation and limit the fire heat to enable the water to wet the heating surfaces as much as possible." In other words, if your circulation be low your furnace temperature must be low too. In order to keep air out of the feed water Mr. Dewrance proposes placing the hot well between the condenser and the air pump, using the latter only for extracting air, and not pumping water also, as at present. The water from the condenser falls into the hot well, and from thence runs into the feed pump by gravity, as it should do in any case. It should be noticed, however, that the feed pump has not the atmospheric pressure to help it, and would be more likely to fail. There is another point to consider. Air in water plays a considerable part in evaporation. It is said that water from which all air has been extracted is not easily turned into steam. Moreover, it is very difficult to ensure that salt water shall never get into a boiler, through a leaky condenser or otherwise, so it is a wise precaution, at the least, to ensure such rapid circulation that bubbles of steam as formed are immediately swept onward, and the metal is never denuded of water long enough to become dry and form the objectionable hydrochloric acid. Mr. Dewrance refers chiefly to steel in his remarks, and this is Nickel natural, because steel has superseded iron as a material for boiler stee plates. That is, the ordinary mild steel made in the open hearth or Siemens-Martin furnace, for Bessemer plates has not, I believe, been used in marine boiler work for many years in this country. There is, however, a description of steel which appears almost to defy the effects of corrosion, but it possesses one terrible defect; it is extremely...