Papurau Newydd Cymru

Chwiliwch 15 miliwn o erthyglau papurau newydd Cymru

Cuddio Rhestr Erthyglau

22 erthygl ar y dudalen hon

TURKISH SOLDIERS.

THE NEW BRITISH IRONCLADS.

[No title]

TORPEDOES.

BREACH OF PROMISE.

EXECUTION AT WINCHESTER.

NAVAL PREPARATIONS.

ITHE DEFENCES OF 1SHE THAMES.

[No title]

THE BRADLAUGH-BESANT APPEAL.

A NEW ANIMAL.

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DOG LICENSES.

THE ORSINI BOMB OUTRAGE AT…

GROSS INHUMANITY IN A WORKHOUSE.".

A SHIP BURNT AT SEA.

THE SANDY POINT MUTINEERS.

[No title]

EXPLOSIONS IN MINES.

Newyddion
Dyfynnu
Rhannu

EXPLOSIONS IN MINES. A short course of lectures on tbia subject was con- cluded on Monday at the Society of Arts by Mr. T. Wills. In the lapt two lectures referenc-o was made to some considerations connected with safety-lamps* the effect of barometric and thermometric alterations, and the part played by coal dust in explosions. As regards eafety-lamps, it has long been known that a strong blast of wind will carry the flaru,» through the gauze and ignite inflammable gas cutside the lamp; but it appears only to have bwn recently made out that a very slight concussion, or even a puff of air, if sufficiently sharp, will have the earne^ effect. This was shown on Monday by tiring a mix-"J? ture of air and gas surrounding a lighted safety-lamp* placed at the end of a long tube by the concussion produced by a pistol shot at the other end, a flexible diaphragm being fixed across the tube to prove that the effect resulted merely from a concussion of air. It was remarked on this that the firing of a shot in a. mine might readily drive tha of a lamp at some distance through the gauze, and so ignite the surrounding firedamp, all the lamps beicg afterwards found uninjured, without anything to show how the accident had been caused. With regard to the photometric value of different lamps the lecturer stated that some interesting had lately been arrived at. With all the English lamp* in which glass is used it is found that the mere addi- tion of the glass chimney or cover diminishes the light by about a third, but with the Muessler or Belsia" lamp the arrangements are so contrived that the addl. tion of the chimney increases the combustion in 8 correapondinardegree, and so there is no loss of light at all. On the point of meteorological changes Mr. WilIt remarked that many great explosions, such as those last autumn at Blantyre and Wigan, could be distinctly traced to falls of the barometer, not immediately before, but some day or two before, and he urged that it was not sufficient to consider only changes in the fe" hours preceding the catastrophe, as had been generally done in such investigations. The effect of 0 mixture of fine coal dust was shown by a striking experiment, in which a perfectly mixture of air with a small proportion of gas fired immediately when a little fine coal dust was shaken up in the bottle containing it. As in many dry minca this dust exists in large quantities, it was evident that it might often be the cause of otherwise inexplicable explosions.

THE PHONOGRAPH.

[No title]

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