2021-04-14 12:43:58

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ENGLISH One pair each of three and one-half inch and five inch compasses, two ruling pens, two pairs of spring dividers, one for pens and one for pencils, a triangular boxwood scale, a common rule, and a hard pencil, are the essential instruments for machine-drawing. At the beginning, when "scratching out" will probably form an item in the work, it is best to use Whatman's paper, or the best roll paper, which, of the best manufacture, is quite as good as any other for drawings that are not water-shaded.

I shuddered at the thought that in these days such barbarities were possible. I asked the soldiers whether I was allowed to enter the burning village, but the commanding sergeant refused his consent.A bevel square is often convenient, but should be an independent one; a T square that has a movable blade is not suitable for general use. Combinations in draughting instruments, no matter what their character, should be avoided; such combinations, like those in machinery, are generally mistakes, and their effect the reverse of what is intended.Presuming the reader to remember what was said of steam hammers in another place, and to be familiar with the uses and general construction of such hammers, let it be supposed steam-hammers, with the ordinary automatic valve action, those that give an elastic or steam-cushioned blow, are well known. Suppose further that by analysing the blows given by hammers of this kind, it is demonstrated that dead blows, such as are given when a hammer comes to a full stop in striking, are more effectual in certain kinds of work, and that steam-hammers would be improved by operating on this dead-stroke principle.

"Is that so? Well, it is not very clear! And that little girl?"67Many clerical gentlemen connected with the University had been ill-treated in the most atrocious manner. The architect Lenertz, a native of Luxemburg, also connected with the University, had been shot, for no reason at all, before the eyes of his wife at the moment that he left the house. And Louvain was so effectively cut off from the outer world that in most convents I was asked whether the rumour was true that the Pope was dead! And at that time his successor had already been appointed.

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A short time after the destruction I was even obliged to accept it for a whole week, as on the same day on which I arrived in Louvain for another visit there was renewed fighting round the town. The Belgians had advanced as far as Rotselair, where the next day they held their ground against overwhelmingly superior numbers; but at last they had to retire, leaving a great many dead behind. The Belgians had even got on to the road Tirlemont-Louvain, and blown up the railway line in two places.He did not seem to mind much the destruction of the Halls with their world-famous wealth of books; anyway he spoke about it in an unconcerned tone. But he seemed to attach great importance to the safety of the town-hall. He said that when the buildings adjoining the town-hall began to burn, he had them blown up in order to keep the fire away from the beautiful monument.They carried all those patients into the cellars on stretchers, and there waited with the nursing staff for the bombardment that had been announced, but never came off.

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.In view of these propositions, I need hardly say to what object machine improvements should be directed, nor which of the considerations named are most affected by a combination of machine functions; the fact is, that if estimates could be prepared, showing the actual effect of machine combinations, it would astonish [70] those who have not investigated the matter, and in many cases show a loss of the whole cost of such machines each year. The effect of combination machines is, however, by no means uniform; the remarks made apply to standard machines employed in the regular work of an engineering or other establishment. In exceptional cases it may be expedient to use combined machines. In the tool-room of machine-shops, for instance, where one man can usually perform the main part of the work, and where there is but little space for machines, the conditions are especially favourable to combination machines, such as may be used in milling, turning, drilling, and so on; but wherever there is a necessity or an opportunity to carry on two or more of these operations at the same time, the cost of separate machines is but a small consideration when compared with the saving of labour that may be effected by independent tools to perform each operation. The tendency of manufacturing processes of every kind, at this time, is to a division of labour, and to a separation of each operation into as many branches as possible, so that study spent in "segregating" instead of "aggregating" machine functions is most likely to produce profitable results.

"But will you then please give me a pass, otherwise I may be detained again on my way back.""It is as I tell you!"For pulleys, gear wheels, or other standard parts of machinery which are not likely to be modified or changed, iron patterns are preferable; patterns for gear wheels and pulleys, when made of wood, aside from their liability to spring and warp, cannot be made sufficiently strong to withstand foundry use; besides, the greatest accuracy that can be attained, even by metal patterns, is far from producing true castings, especially for tooth wheels. The more perfect patterns are, the less rapping is required in drawing them; and the less rapping done, the more perfect castings will be.

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Presuming the reader to remember what was said of steam hammers in another place, and to be familiar with the uses and general construction of such hammers, let it be supposed steam-hammers, with the ordinary automatic valve action, those that give an elastic or steam-cushioned blow, are well known. Suppose further that by analysing the blows given by hammers of this kind, it is demonstrated that dead blows, such as are given when a hammer comes to a full stop in striking, are more effectual in certain kinds of work, and that steam-hammers would be improved by operating on this dead-stroke principle.2. The necessity for, and consequent saving effected by, power-machinery for handling is mainly in vertical lifting, horizontal movement being easily performed by hand.

CHAPTER VIII

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Apr-14 12:43:58