This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1868 edition. Excerpt: ... be looked for only from a radical change in the valves and movements. It should be observed, however, that the velocity of piston at which diagrams Nos. 9 and 10 were drawn was 600 feet per minute. Another cause often contributes largely to injure the steam-line, especially in condensing engines- ...
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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1868 edition. Excerpt: ... be looked for only from a radical change in the valves and movements. It should be observed, however, that the velocity of piston at which diagrams Nos. 9 and 10 were drawn was 600 feet per minute. Another cause often contributes largely to injure the steam-line, especially in condensing engines--namely, the condensation of the steam on entering the cylinder; and to this the enormous fall of pressure in diagram No. 15 must undoubtedly be in part attributed, the smallness of the ports not being sufficient to account for it. III. The Expansion Curve. One of the most important uses of the Indicator is to demonstrate the correctness of the theory of expansion, the economy of working steam expansively, its practical limitations, and the value of the various means employed for cutting off the steam. The opposite diagram is drawn to illustrate the theory of expansion, which is that steam, being perfectly elastic, follows the law of the gases, known as Mariotte'sor Boyle's law, that the volume of a given weight of gas is inversely as the pressure to which it is subjected. Accordingly we see in this diagram, that in all cases where the volume is doubled the pressure is diminished by one-half, and so on, the volume multiplied by the pressure giving always a constant product. The pressure of steam represented is 100 lbs. above the perfect vacuum divided by lines drawn parallel with the atmospheric line, into 20 divisions of 5 lbs. each. The length of the stroke is divided into 24 equal divisions, by lines drawn perpendicular to the atmospheric line. The curves show the expansion of the steam, when cut off at Y, $ i, f, i, i, ana-7?n f the stroke; the figures at the termination of each curve represent the pressure of steam at the termination of..
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