. The Locomotive . he steam to developits power. In this respect, therefore, the two machines are widelydifferent. The similarity in fundamental principles is based on otherconsiderations and is a matter we shall now discuss. Let us suppose that we have a specially constructed boiler, engineand connecting steam pipe, all built with the same cross section asshown in Fig. 2 on the opposite page. Suppose further that steam hasbeen generated at some given pressure, until all the space is filledbetween the surface of the water in the boiler and piston in the might consider that the spac
. The Locomotive . he steam to developits power. In this respect, therefore, the two machines are widelydifferent. The similarity in fundamental principles is based on otherconsiderations and is a matter we shall now discuss. Let us suppose that we have a specially constructed boiler, engineand connecting steam pipe, all built with the same cross section asshown in Fig. 2 on the opposite page. Suppose further that steam hasbeen generated at some given pressure, until all the space is filledbetween the surface of the water in the boiler and piston in the might consider that the space mentioned is filled with several unitvolumes of steam in contact with each other, as indicated by the dottedlines in the boiler and steam pipe, and of such a size that each weighsone pound. Now we can cause the piston to move and to increasethe volume between it and the position shown in the sketch by pro- I92I. THE LOCOMOTIVE OO •Slidinq gate or shutter to*,;2. cyirtder ■*■ steam pipe ►Cyirider. (hieing or generatinganother unit vohmie ofsteam at the surface ofthe water in the do this, heat, ofcourse, is required. The changes involume and pressurethat take place in thisimaginary engine cyl-inder can be chartedon a diagram similar tothat in Fig. i. Thisdiagram is given inFig. 3, and the line AB which represents the increase in volume atconstant pressure within the cylinder is exactly similar to the lineAB of Fig. I. Suppose next that the sliding gate or shutter at the head end ofthe cylinder is closed, thereby preventing the entry of any more steaminto the cylinder. The entrapped steam will then expand, drivingthe piston further along in the cylinder and the pressure-volumechange may be represented by the line BC of Fig. 3 which is similarto the line BC of Fig. i. In Fig. I we had the engineexhausting to the atmosphere whichis a space of constant pressure. Inthe present arrangement we shallsubstitute a condenser which, beingconstantly cooled by wat
Size: 1792px × 1395px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauth, bookcentury1800, bookdecade1860, bookidlocomotive32hart
