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. 1889 Excerpt: ...cylinder, which consequently has a tendency to wear unevenly. Up till about the year i860 the majority of mercantile screw engines were horizontal, but since that date the great advantages of the inverted cylinder type have become more and more fully recognised, and at the present moment the system is in almost ...
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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. 1889 Excerpt: ...cylinder, which consequently has a tendency to wear unevenly. Up till about the year i860 the majority of mercantile screw engines were horizontal, but since that date the great advantages of the inverted cylinder type have become more and more fully recognised, and at the present moment the system is in almost universal use. Even in ironclad war-ships, fitted with twin screws, the vertical engine is now frequently employed, as it has been found possible to get the whole of the machinery, with the exception of parts of the cylinders, below the water-level, and the little that projects above can be easily protected by side and horizontal armour, as well as by the side coal bunkers. Students visiting the Museum can study this variety of the screwengine in the simplest form in the pair of small yacht engines by Messrs. Davis & Co., the parts of which can be readily examined as there is no condenser to hide them. They can next inspect the large model of the engines of the Lopez, by Messrs. Denny Brothers, of Dumbarton. In these engines the condenser occupies the space between the cylinders, and projects beyond the framing on each side. It will be noticed that there are two piston-rods to each cylinder, which are connected together by a long cross-head, off the end of which, prolonged, the air and other pumps are driven. There are several other inverted cylinder engines in the Museum; but, as they all belong to the compound type, they will be referred to hereafter. CHAPTER V. THE ERA OF SURFACE CONDENSATION AND COMPOUND ENGINES. Although the modern theory of heat was not understood in the early days of steam navigation, nevertheless engineers were well aware, even at that time, of the direction in which they would have to move in order to improve the economi...
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