2021-04-14 11:50:04

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ENGLISH 8. The expense of the appliances of distribution and their maintenance.The permanent contraction of steel in tempering is as the degree of hardness imparted to it by the bath.Referring first to the saving effected by combining several operations in one machine, there is perhaps not one constructor in twenty that ever stops to consider what is really gained, and perhaps not one purchaser in a hundred that does the same thing. The impression is, that when one machine performs two operations it saves a second machine. A remarkable example of this exists in the manufacture of combination machines in Europe for working wood, where it is common to find complicated [69] machines that will perform all the operations of a joiner's shop, but as a rule only one thing at a time, and usually in an inconvenient manner, each operation being hampered and interfered with by another; and in changing from one kind of work to another the adjustments and changes generally equal and sometimes exceed the work to be done. What is stranger still is, that such machines are purchased, when their cost often equals that of separate machines to perform the same work.

To exert a powerful force acting through but a short distance, percussive devices are much more effective and simple than those acting by maintained or direct pressure. A hammer-head may give a blow equal to many tons by its momentum, and absorb the reactive force which is equal to the blow; but if an equal force was to be exerted by screws, levers, or hydraulic apparatus, we can easily see that an abutment would be required to withstand the reactive force, and that such an abutment would require a strength perhaps beyond what ingenuity could devise.By examining automatic hammers it will be found that their valves are connected to the drop by means of links, producing [162] coincident movement of the piston and valve, and that the movement of one is contingent upon and governed by the other. It will also be found that these connections or links are capable of extension, so as to alter the relative position of the piston and valve, thereby regulating the range of the blow, but that the movement of the two is reciprocal or in unison. Reasoning inductively, not discovering or inventing, it may be determined that to secure a stamp blow of a hammer-head, the valve must not open or admit steam beneath the piston until a blow is completed and the hammer has stopped.INTRODUCTION

And over these nervous and terrified thousands at Maastricht rolled from afar the dull roar of the guns, thunder-like bursts from which had frightened them so terribly.As Professor Noyons heard that other hospitals, churches, and ancient buildings were not spared either, he went to the commanding officer through the rain of bullets, clad in his white overalls, to claim protection for everything that lawfully displayed the Red Cross flag, and to request that churches, convents, ancient buildings, and especially the town-hall should be spared. It is only owing to his intervention that not much more was destroyed in Louvain.I witnessed Pastor Claes's labours for a moment only, for the smell was unbearable even at a somewhat considerable distance. The good pastor persevered in the work after having started it, with the assistance of some faithful helpers, who all of them had sealed their mouths with a sponge soaked in some disinfectant. The corpses were taken from the cave, money and documents put away in separate bags, and the unfortunate owners coffined and blessed.

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I went up to them and explained that there was no need at all to be afraid of me. They were able to give me news of the inhabitants of Villa Rustica. The owner had died a few days since, from a paralytic stroke, brought on by the emotions caused by the German horrors, whereas madame, who had heroically intervened on behalf of some victims, was probably at St. Hadelin College.We had got near the door of the room that stood ajar, and from there came the sound of a couple of girls' voices: "Hail, Mary.... Hail, Mary...."(1.) What analogy may be found between steam and water power?(2.) What is the derivation of the name turbine?(3.) To what class of water-wheels is this name applicable?(4.) How may water-wheels be classified?(5.) Upon what principle does a reaction water-wheel operate?(6.) Can ponderable weight and pressure be independently considered in the case?(7.) Why cannot radial running joints be maintained in machines?(8.) Describe the mechanism in common use for sustaining the weight of turbine wheels, and the thrust of propeller shafts.

The sight of that small group, hidden among the green foliage, was as brilliant as it was surprising. One of the officers, clearly the highest in rank, summoned us to come nearer, and asked the soldiers for an explanation. Standing smartly at attention, they gave it, as a school-child might haltingly recite a lesson learned by heart. The officer whom I thought it convenient to call "Captain" looked searchingly at me and then began:

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There lay also a woman, with one leg amputated. Her husband had been murdered, another bullet had entered the leg of the baby in her arms. Another woman had her child murdered in her arms.(1.) Name five machines as types of those employed in the general processes of converting material.(2.) Name some machines, the object of which is to augment forceOne to attain speedOne directed to the guidance of tools.(3.) What is the difference between the hot and cold treatment of iron as to processesAs to dimensions? (4.)

My request to allow the child to stay at the caf for half an hour was granted, and I went through the village towards the place whence the German batteries sent their destructive fire. At last I got as far as the top of a hill, from which I could see two forts shrouded in a cloud of smoke, which was also the case with the German batteries."They were all unrecognisable, their faces were black from smoke, their uniforms in rags, their hands covered with blood. The general was put on a stretcher, and carried outside the fort across the heaps of obstacles; there he was attended to by a surgeon. He had lost consciousness. As soon as he recovered it, he pressed the hands of two Belgian officers. 'It is all over; there is nothing left to defend. But we did our utmost courageously.'It is strange, considering the simplicity of construction and the very important office filled by machines for cutting on plane surfaces, that they were not sooner invented and applied in metal work. Many men yet working at finishing, can remember when all flat surfaces were chipped and filed, and that long after engine lathes had reached a state of efficiency and were generally employed, planing machines were not known. This is no doubt to be accounted for in the fact that reciprocal movement, except that produced by cranks or eccentrics, was unknown or regarded as impracticable for useful purposes until late years, and when finally applied it was thought impracticable to have such movements operate automatically. This may seem quite absurd to even an apprentice of the present time, yet such reciprocating movement, as a mechanical problem, is by no means so simple as it may at first appear.

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