Spons' dictionary of engineering, ed. by O. Byrne (and Spon). 8 div, Volume 81 |
Termos e frases comuns
abutment acid angle applied arch arrangement atmosphere axis battery blocks boiler brake brake carriages brake-blocks bricks bridge cables carriages cells centre charges chords circuit coefficient of friction compression connected construction copper curve cylinder depth diameter direction distance dough effect engine equal experiments explosion extrados fire fixed flues friction fuze girders gutta-percha heat hole horizontal horizontal action iron ironstone ITAL kilogrammes length lever liquid load lower machine means mercury metal mètres millimètres motion nitrate of soda nitric acid nitro-glycerine obtained parabola passing percussion cap piers piston placed plates platinum pressure produced pump quantity radius represented resistance rods rolling friction screw shaft shale shown in Fig side sliding span steam sufficient surface temperature tension thickness tons train truss tubes upper velocity vertical voussoirs wedges weight wheels wire zinc
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Página 539 - ... the other two perforations, which are parallel to each other on each side of the central one, and at right angles to it, serve for the reception of the circuit wires. The arrangement for securing the connection of these with the insulated wires in the fuzes is as follows : — The piece of double covered wire above referred to is originally of a sufficient length to allow of the gutta-percha being removed from about one-and-ahalf inches of the wires.
Página 419 - France, which was in progress of construction in the year 1828; but the expedient was not successful; the tubes became furred with deposit, and burned out* " Other engines, with boilers of a variety of construction, were made, all having in view the increase of the heating surface, as it then became obvious to my father that the speed of the engine could not be increased without increasing the evaporative power of the boiler. Increase of surface was in some cases obtained by inserting two tubes,...
Página 418 - These results show a large increase above the standard in every respect. The prevention of smoke was, we may say, practically perfect, whether the fuel burned was 15 Ibs. or 27 Ibs.
Página 443 - Fig. 10, is allowed to be lifted off its face by the pressure of the water, and lets the water flow past the pump direct through into the tubes. The fire is then lighted and steam raised from the water in the tubes, which starts the circulating pump to work. More water is forced through the tubes by the circulating pump than is evaporated in them. The circulating pump of the boiler now used for ten months is double-acting, 6 inches in diameter with 9 inches stroke, and makes 40 revolutions per minute...
Página 585 - ... pulley. The friction pulley was made of great thickness for two reasons. When the pulley is heated, the arms cease to be in contact with the interior circumference of the pulley, consequently they would not prevent the pressure of the brake from altering the form of the pulley. This renders great stiffness necessary in the pulley itself. Again, it is found that a heavy friction pulley insures more regularity in the motion, operating, in fact, as a fly-wheel, in equalizing small irregularities....
Página 542 - They were thus ready for insertion into the bag or other receptacle containing the charge of gunpowder, the ends of the covered wires protruding from the opening of the latter to a convenient distance for effecting the junction with the branch and earth-wires.
Página 507 - On the wood cylinder a spiral groove is cut, and at one of its extremities a brass ring is fixed, to which is attached one of the ends of a long wire of very small diameter, which when coiled round the wood cylinder fills the entire groove, and is fixed at its other end to the remote extremity of the brass cylinder. Two springs...
Página 588 - ... and prevent it from shaking when the carriage is running. The wear of the shoe is provided for by inserting two small dovetailed pieces, F and G, at the points where the wear takes place; these pieces are slightly tapered, and are driven into their places from the inner side, being burred or rivetted on the opposite side, where they remain firmly fixed, having no tendency to work loose. The lower piece is of wrought iron, which is found to answer best for the purpose ; the upper one, F, which...
Página 584 - If protected blasting liquid be kept in a closed vessel, it will remain in that state for an indefinite period of time, and ready at any moment to be reduced or rendered fit for action ; if, however, it be exposed in an open vessel, it will regain its explosiveness, in periods of time proportionate to the amount or degree of exposure.
Página 572 - ... ft. in length, and at a distance of 14 ft. from its extremity, which was nearly vertical. At a depth of 8 ft., a vault filled with clay was found, in consequence of which the bottom of the hole was tampe<l, leaving a depth of 7 ft.