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    Software name: appdown
    Software type: Microsoft Framwork

    size: 283MB

    Lanuage:Englist

    Software instructions

      In compression processes no material is cut away as in cutting or grinding, the mass being forced into shape by dies or forms that give the required configuration. The action of compressing machines may be either intermittent, as in the case of rolling mills; percussive, as in steam hammers, where a great force acts throughout a limited distance; or gradual and sustained, as in press forging. Machines of application, for abrading or grinding, are constantly coming more into use; their main purpose being to cut or shape material too hard to be acted upon by compression or by cutting processes. It follows that the necessity for machines of this kind is in proportion to the amount of hard material which enters into manufactures; in metal work the employment of hardened steel and iron is rapidly increasing, and as a result, grinding machines have now a place among the standard machine tools of a fitting shop.Eighth.Rapping plates, draw plates, and lifting irons for drawing the patterns out of the moulds; fallow and match boards, with other details that are peculiar to patterns, and have no counterparts, neither in names nor uses, outside the foundry.


      They made also sad havoc of the Boulevard de Namur. Many mansions of the aristocracy had been destroyed and many people killed. There were corpses still lying on the Boulevard as I passed, all in a state of decay. The smell was unbearable and the sight loathsome, especially when I saw several drunken soldiers insulting the bodies of these unfortunate people."I require that everywhere a strict investigation shall take place into the conduct of the soldiers with regard to the life and property of the civilian population.


      In the manufacture of machines, there are usually so many sizes and modifications, that drawings should assist and determine in a large degree the completeness of classification and record. Taking the manufacture of machine tools, for example: we cannot well say, each time they are to be spoken of, a thirty-six inch lathe without screw and gearing, a thirty-two inch lathe with screw and gearing, a forty-inch lathe triple geared or double geared, with a twenty or thirty foot frame, and so on. To avoid this it is necessary to assume symbols for machines of different classes, consisting generally of the letters of the alphabet, qualified by a single number as an exponent to designate capacity or different modifications. Assuming, in the case of engine lathes, A to be the symbol for lathes of all sizes, then those of different capacity and modification can be represented in the drawings and records as A1, A2, A3, A4, and so on, requiring but two characters to indicate a lathe of any kind. These symbols should be marked in large plain letters on the left-hand lower corner of sheets, so that the manager, workman, or any one else, can see at a glance what the [86] drawings relate to. This symbol should run through the time-book, cost account, sales record, and be the technical name for machines to which it applies; in this way machines will always be spoken of in the works by the name of their symbol.As a rule, ornament should never be carried further than graceful proportions; the arrangement of framing should follow as nearly as possible the lines of strain. Extraneous decoration, such as detached filagree work of iron, or painting in colours, is [159] so repulsive to the taste of the true engineer and mechanic that it is unnecessary to speak against it.

      The End(1.) Why is the effect produced different on the top and bottom of a piece when struck by a hammer?(2.) Why does not a compound hammer create jar and concussion?(3.) What would be a mechanical difficulty in presenting the material to such hammers?(4.) Which is most important, speed or weight, in the effect produced on the under side of pieces, when struck by single acting hammers?

      3. Never heard any German soldier, of whatever rank, assert that he himself had witnessed any action by a franc-tireur, although I questioned such soldiers times without number. They always mentioned others, who had left days ago, and were said to have gone through the miserable experience!


      Although a system but recently developed, the employment of hydraulic machinery for transmitting and applying power has reached an extended application to a variety of purposes, and gives promise of a still more extensive use in future. Considered as a means of transmitting regularly a constant amount [54] of power, water apparatus is more expensive and inferior in many respects to belts or shafts, and its use must be traced to some special principle involved which adapts hydraulic apparatus to the performance of certain duties. This principle will be found to consist in storing up power in such a manner that it may be used with great force at intervals; and secondly, in the facilities afforded for multiplying force by such simple mechanism as pumps. An engine of ten-horse-power, connected with machinery by hydraulic apparatus, may provide for a force equal to one hundred horse-power for one-tenth part of the time, the power being stored up by accumulators in the interval; or in other words, the motive power acting continuously can be accumulated and applied at intervals as it may be required for raising weights, operating punches, compressive forging, or other work of an intermittent character. Hydraulic machinery employed for such purposes is more simple and inexpensive than gearing and shafts, especially in the application of a great force acting for a considerable distance, and where a cylinder and piston represent a degree of strength which could not be attained with twice the amount of detail, if gearing, screws, levers, or other devices were employed instead.

      During the evening I was granted an audience by the Right Reverend Monseigneur Rutten, Bishop of Lige. The venerable, aged prelate received me very affably, but he was deeply impressed by the terrible fate that had overwhelmed his poor native country. He himself had suffered exceedingly bad treatment at the hands of the Germans. First he and the other hostages were imprisoned in the citadel, where he was locked up in a small shanty, with a leaking roof, so that the torrential rain entered it freely. Wet and cold, the Bishop passed that day without being offered any food, and, as stated above, was at last allowed to go home.Many things had happened at Vis since my first visit. Under the pretext that the church spire could indicate to Fort Pontisse in which direction to shoot, paraffin had been poured over church and spire and fire set to them. It was a venerable ancient structure, built ten centuries ago, the fine stained windows of which were well known.

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      Designing machines must have reference to adaptation, endurance, and the expense of construction. Adaptation includes the performance of machinery, its commercial value, or what the machinery may earn in operating; endurance, the time that machines may operate without being repaired, and the constancy of their performance; expense, the investment represented in machinery.

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      A short distance beyond this little caf lies the large bridge across the Meuse. Before the Germans arrived it was partly destroyed by the Belgians, but so inadequately that obviously the enemy could repair it easily. Bombs were therefore fired regularly from Fort Pontisse at the bridge, and only an hour ago it had been hit, with the result that a big hole was made in the undamaged part. In the road also big holes were made by the exploding projectiles. Having passed underneath the viaduct of the bridge, I found myself opposite Vis on the sloping bank of the Meuse. Two boys had been commanded by the Germans to work the ferry-30boat for them, and after I had shown them my passport, they took me to the other side.5. The lubrication of surfaces working under air pressure, such as the pistons and valves of engines.

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      "Then a frightful thing happened. The men had finished65 breakfast, some were sleeping quietly in spite of the thundering noise. The assault was expected to commence during the next night.


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