. Railway and locomotive engineering : a practical journal of railway motive power and rolling stock . dupwards, and by this operation thepumping of water from the mine orother work was carried on. Therewas. properly speaking, no steam pres- sure. The water was usually iit bail-ing at all, the lid or boiler covering be-ing left as often open as not. Thepurpose of usiiiK the jet of steam >vasin tlie production of the vacuum, sothat the power of the engine camefrom the atmosphere rushing into thecylinder space made vacant by the con-densation of the steam jet. This wasthe kind of engine a mod
. Railway and locomotive engineering : a practical journal of railway motive power and rolling stock . dupwards, and by this operation thepumping of water from the mine orother work was carried on. Therewas. properly speaking, no steam pres- sure. The water was usually iit bail-ing at all, the lid or boiler covering be-ing left as often open as not. Thepurpose of usiiiK the jet of steam >vasin tlie production of the vacuum, sothat the power of the engine camefrom the atmosphere rushing into thecylinder space made vacant by the con-densation of the steam jet. This wasthe kind of engine a model of whichcame into Watts hands in 1763. It may be noted that previous tothis Watt had been experimenting withsteam, making many decisive tests ofthe elasticity of steam. Among thesehe found that a cubic inch of waterwill form a cubic foot of steam, witlia pressure equal to the also discovered the remarkablephenomenon that when a cubic foot otsteam is condensed by injecting coldwater, as much heat is given out aswould raise six cubic inches of waterto the boiling point. He also dis-. covered that the latent heat of steamdecreases as the sensible heat increases,and that universally these two addedtogether made a constant quantity,which is the same for all tempera-tures. It appears that Watts first thoughtson the steam engine were in the direc-tion of traveling carriages, but New-comens engine coming into his handsset his mind in the direction of thestationary steam engine. He experi-mented for several years and finallyconceived the idea of condensing thesteam in a separate vessel, keeping thecylinder at a constant degree of was only after working step bystep slowly, but most effectually, thatthe new creation began to assumeform in the mind of the master mech-anician. The condensation of steamin a separate vessel, the use of a con-stant vacuum, caused by a pump at-tached to the beam, the covering upof both ends of the cylinder, the ad- mission of steam at a
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectrailroa, bookyear1901
