Part 36 (1/2)

The practice then was to employ a furnace, placed at the bottom of the upcast shaft of the coal-pit, to produce the necessary ventilation

This practice was highly riskful It was dangerous as well as ineffective It was also liable to total destruction when an explosion occurred, and the ently required The ventilation of s, had been proposed by a Gereured in his work entitled De Re Metalicat, p 162 But in all cases in which this systees of a mine has been tried, it has invariably been found unsuccessful as aFans draw in the air at their centres, and expel it at their circumference, it occurred to me that if ere to make a communication between the upcast shaft of thethe top of the upcast shaft, a Fan so arranged would draw out the foul air from the mine, and allow the fresh air to descend by the downcast shaft, and so traverse the workings And as a Suction Fan so placed would be on the surface of the ground, and quite out of the way of any risk of injury--being open to view and inspection at all times--we should thus have an effective and trustworthycon for my Direct Action Suction Fan for coal-pit ventilation to the Earl Fitzwilliaent Mr Hartop, in 1850, his lordshi+p was so much pleased with it that I received an order for one of 14 feet diaest coalpits I arranged the steae Fan, so as to be a part of it; and by placing the crank of the engine on the end of the Fan-shaft, the engine transferred its power to it in the h satisfaction which this Ventilating Fan gave to the Earl and to all connected with his coal- orders for several of them

I took out no patent for the invention, but sent drawings and descriptions to all whom I knew to be interested in coalmine ventilation

I read a paper on the subject, and exhibited the necessary drawings, at theof the British association at Ipswich in 1851 These were afterwards published in the Mining Journal The consequence is thatFans are now in successful action at home and abroad

1845 An improvement in the Links of Chain Cables

1845 An I Iron

One of the most important processes in connection with the production of the details of machinery, and other purposes in which , namely, when more or less complex forms are, so to speak, ”built up” by the union of suitable portions of malleable iron united and incorporated with each other in the process of welding This consists in heating the parts which we desire to unite to a white heat in a se fire, or in an air furnace, by means of which that peculiar adhesive ”wax-like” capability; of sticking together is induced,--so that when the several parts are forcibly pressed into close contact by blows of a hammer, their union is rendered perfect

But as the intense degree of heat which is requisite to induce this adhesive quality is accos tenaciously to the white-hot surfaces of the iron, the union will not be co ed and driven out fro If by any want of due care on the part of the smith, the surfaces be concave or have hollows in them, the scoriae will be sure to lurk in the recesses, and result in a defective welding of a h the exterior may display no evidence of the existence of this fertile cause of failure, yet some undue or unexpected strain will rend and disclose the shut-up scoriae, and probably end in soures will perhaps serve to render my remarks on this truly ie]

Fig1 represents an imperfectly prepared surface of two pieces of malleable iron about to be welded The result of their concavity of form is that the scoriae are almost certain to be shut up in the hollow part,--as the pieces will unite first at the edges and thus include the scoriae, which no ae They will re2 Happily, theall such treacherous risks are as sihly effective All that has to be done to render their occurrence next to iive to the surfaces we desire to unite by welding a convex for 3; the result of which is that we thus provide an open door for the scoriae to escape from between the surfaces,--as these unite first in the centre, as due to the convex form, and then the union proceeds outwards, until every particle of scoriae is expelled, and the union is perfectly coency

Fig 4 represents the final and perfect co, which is effected by this co the surfaces a convex form instead of a concave one

When I was called by the Lords of the Admiralty in 1846 to serve on a Coate the causes of failure in the wrought-iron smith work of the navy, many sad instances came before us of accidents which had been caused by defective welding, especially in the vitally important articles of Anchors and Chain Cables

In the case of the occasional failure of chain cables, the cause was generally assigned to defective material; but circumstances led me to the conclusion that it was a question of workmanshi+p or maltreatment of what I knew to be of excellent material I therefore instituted a series of experiments which yielded conclusive evidence upon the subject; and which proved that defective welding was the main and chief cause of failure In order to prove this, several apparently excellent cables were, by the aid of ”the proving machine,” pulled to pieces, link by link, and a careful record was kept of the nature of the fracture The result was, that out of every 100 links pulled asunder 80 cases clearly exhibited defective welding; while only 20 were broken through the clear sound metal This yielded a very important lesson to those specially concerned

1845 Introduction of the V Anvil

In connection with reat cylindrical shafts, I introduced what I termed my V anvil

Its employment has most importantly contributed to secure perfect soundness in such class of forgings

In the old syste cylindrical shafts, the bar was placed upon a flat-faced anvil The effect of each blow of the hammer upon the as to knock the shaft into an oval for 1); and the inevitable result of a succession of such bloas destruction of the soundness of the centre or axis of the shaft

[i from the employment of a flat-faced anvil, I introduced2), the effect of which was, that the dispersive action of the blow of the ha action, which ensured the perfect soundness of the work; while the V or fork-like forle face kept the work steadily under the centre of the ha the scale or scoriae to fall into the apex or botto the faces of the angle quite clear

This sienerally adopted, and has been productive of most satisfactory and ihted Safety Valve

Having been on several occasions called to investigate the causes of steam boiler explosions, my attention was naturally directed to the condition of the Safety Valve I found the construction of them in many cases to be defective in principle as well as inchiefly from the employment of a conical foruide spindle to enable it to keep in correct relative position to its corresponding conical seat, as seen at A in Fig 1 As this guide spindle is always liable to be clogged with thewater, which yields a very adhesive encrustation, the result is a very riskful tendency to impede the free action of the Safety Valve, and thereby prevent its serving its purpose

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