Handbook for Mechanical Engineers |
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angle beam belt blister steel body boiler bolts brass carbon cast iron cent centre chain coal compression copper Cornish crane crank cubic cubic foot cylinder deflection diam diameter elasticity Electrical energy equal evaporate factor of safety feet per second FIELD LESSON fire-grate flange flue foot force friction furnace Gamboge gases gauge gearing girders gravity heating surface HYDRAULIC HYDRAULIC MACHINERY indicator diagram LECTURE length lift machine machinery maximum metal modulus motion mould ordinary pipes piston pitch plate pressure in lbs proportion Prussian blue pulleys pump quantity radians radius ratio resistance revolutions per minute rivet rope Safe load screw sectional area shaft shearing side speed square inch steam strain strength stroke temperature tension thickness threads tubes unit valve velocity Vis viva weight welding wheel width wrought iron Zinc دو وو
Popular passages
Page 142 - If an engine be such that, when it is worked backwards, the physical and mechanical agencies in every part of its motions are all reversed, it produces as much mechanical effect as can be produced by any thermodynamic engine, with the same temperatures of source and refrigerator, from a given quantity of heat.
Page 141 - It is impossible for a self-acting machine, unaided by any external agency, to convey heat from one body to another at a higher temperature ; or heat cannot of itself (that is, without compensation) pass from a colder to a warmer body.
Page 8 - The total energy of any body or system of bodies is a quantity which can neither be increased nor diminished by any mutual action of such bodies, though it may be transformed into any one of the forms of which energy is susceptible.
Page 141 - FIRST LAW OF THERMODYNAMICS. Heat and mechanical energy are mutually convertible, and heat requires for its production, and produces by its disappearance, mechanical energy in the proportion of...
Page 133 - Unit, or unit of heat, is the quantity of heat required to raise 1 Ib. of pure water, at its point of maximum density (=39-1° F.), through 1° F.
Page 141 - It is impossible, by the unaided action of natural processes, to transform any part of the heat of a body into mechanical work, except by allowing heat to pass from that body into another at a lower temperature.
Page 141 - It is impossible by means of inanimate material agency, to derive mechanical effect from any portion of matter by cooling it below the temperature of the coldest of the surrounding objects.
Page 35 - TOUGHENED CAST IRON. Toughened cast iron is produced by adding to the cast iron, and melting amongst it, from one-fourth to one-seventh of its weight of wrought-iron scrap, which removes some of the carbon from the cast iron, and causes an approximation to steel.
Page 53 - ... be much diminished, and such a magnitude may be assigned, that the weight of the body must exceed its strength, and it not only would be unable to support any load, but would actually fall to pieces by its own weight. The strength of a structure of any kind is not, therefore, to be determined by that of its model, which will always be much stronger in proportion to its size. All works, natural and artificial, have limits of magnitude which, while their materials remain the same, they cannot surpass....
Page 142 - Carnot was the first to assert the law, that the ratio of the maximum mechanical effect to the whole heat expended in an expansive machine, is a function solely of the two temperatures at which the heat is respectively received and emitted, and is independent of the nature of the working substance.