2021-04-17 01:26:33

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ENGLISH "1. That it is prohibited to be out of doors after seven o'clock (Belgian time) in the evening.There is, however, a principle in hydraulic machinery that must be taken into account, in comparing it with positively geared mechanism, which often leads to loss of power that in many cases will overbalance any gain derived from the peculiar action of hydraulic apparatus. I allude to the loss of power incident to dealing with an inelastic medium, where the amount of force expended is constant, regardless of the resistance offered. A hydraulic crane, for instance, consumes power in proportion to its movements, and not as the amount of duty performed; it takes the same quantity of water to fill the cylinders of such cranes, whether the water exert much or little force in moving the pistons. The difference between employing elastic mediums like air and steam, and an inelastic medium like water, for transmitting force in performing irregular duty, has been already alluded to, and forms a very interesting study for a student in mechanics, leading, as it does, to the solution of many problems concerning the use and effect of power.

This he had done. Already for many days he had treated several officers to his best claret.A pattern-maker no sooner sees a casting than he imagines the kind of pattern employed in moulding it; a moulder will imagine the plan of moulding and casting a piece; while an engineer will criticise the arrangement, proportions, adaptation, and general design, and if skilled, as he ought to be, will also detect at a glance any useless expense in patterns or moulding.

"Great German defeat at Libramontnine thousand prisoners taken."Shaping machines are divided into two classes, one modification with a lateral feed of the tools and cutter bar, technically called "travelling head machines," the other class with a feed motion of the table which supports the work, called table-feeding machines. The first modification is adapted for long pieces to be planed transversely, such as toothed racks, connecting rods, and similar work; the second class to shorter pieces where much hand adjustment is required.

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"Yes, that the French are advancing towards Lige, and that the British have landed in Belgium."Between two of my several trips to Louvain I made one to Namur in the beginning of September, after having secured at Lige, by a trick, a splendid permit which enabled me to travel even by motor-car.116

(1.) What does the term "machinery of transmission" include, as applied in common use?(2.) Why cannot direct comparisons be made between shafts, belts, and gearing?(3.) Define the relation between speed and strain in machinery of transmission.(4.) What are the principal conditions which limit the speed of shafts?"No, I've none to sell."A safe rule will be to assume that machinery mainly used and seen by the skilled should be devoid of ornament, and that machinery seen mainly by the unskilled, or in public, should have some ornament. Steam fire engines, sewing machines, and works of a similar kind, which fall under the inspection of the unskilled, are usually arranged with more or less ornament.

As remarked in a previous place, no one can expect to prepare successful designs for machinery, who does not understand the details of its construction; he should know how each piece is moulded, forged, turned, planed, or bored, and the relative cost of these processes by the different methods which may be adopted.By assuming this or any other well-proved example, and estimating larger or smaller shafts by keeping their diameters as the cube root of the power to be transmitted, the distance between bearings as the diameter, and the speed inverse as the diameter, the reader will find his calculations to agree approximately with the modern practice of our best engineers. This is not mentioned to give proportions for shafts, so much as to call attention to accidental strains, such as winding belts, and to call attention to a marked discrepancy between actual practice and such proportions as would be given by what has been called the measured or determinable strains to which shafts are subjected.

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The general expatiated once more on the francs-tireurs of Louvain, and asked me to explain in my papers without fail that the citizens had to thank themselves for what had happened. The sergeant who had taken me to him was ordered to escort me, that I might not have any further trouble with the soldiers in the city.The first principle to be pointed out in regard to belts, to distinguish them from shafts as a means of transmitting power, is that power is communicated by means of tensile instead of torsional strain, the power during transmission being represented in the difference of tension between the driving and the slack side of belts. In the case of shafts, their length, or the distance to which they may be extended in transmitting power, is limited by torsional resistance; and as belts are not liable to this condition, we may conclude that unless there are other difficulties to be contended with, belts are more suitable than shafts for transmitting power throughout long distances. Belts suffer resistance from the air and from friction in the bearings of supporting pulleys, which are necessary in long horizontal belts; with these exceptions they are capable of moving at a very high rate of speed, and transmitting power without appreciable loss.The streets and squares where the high military officers had established themselves were closed by cordons of soldiers, and nobody was allowed to pass them.

131On the way I was stopped by two soldiers, one of whom examined my papers, and, finding that I was a journalist, revealed himself as a colleague, in ordinary times editor of the K?lnische Zeitung. He shook both my hands quite excitedly, glad to meet a colleague, and, better still, one from the "friendly" Netherlands.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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Apr-17 01:26:33