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IMPROVED FIRE-DAMP DETECTER.

According to the London Mining Journal, Mr. W.E.  Garforth, of Normanton, has introduced an ingenious invention, the object of which is to detect fire-damp in collieries with the least possible degree of risk to those engaged in the work.  Mr. Garforth’s invention, which is illustrated in the diagram given below, consists in the use of a small India rubber hand ball, without a valve of any description; but by the ordinary action of compressing the ball, and then allowing it to expand, a sample of the suspected atmosphere is drawn from the roof, or any part of the mine, without the great risk which now attends the operation of testing for gas should the gauze of the lamp be defective.  The sample thus obtained is then forced through a small protected tube on to the flame, when if gas is present it is shown by the well-known blue cap and elongated flame.  From this description, and from the fact that the ball is so small that it can be carried in the coat pocket, or, if necessary, in the waistcoat pocket, it will be apparent what a valuable adjunct Mr. Garforth’s invention will prove to the safety-lamp.  It has been supposed by some persons that explosions have been caused by the fire-trier himself, but owing to his own death in most cases the cause has remained undiscovered.  This danger will now be altogether avoided.  It is well known that the favorite form of lamp with the firemen is the Davy, because it shows more readily the presence of small quantities of gas; but the Davy was some years ago condemned, and is now strictly prohibited in all Belgian and many English mines.  Recent experience, gained by repeated experiments with costly apparatus, has resulted in not only proving the Davy and some other descriptions of lamps to be unsafe, but some of our Government Inspectors and our most experienced mining engineers go so far as to say that “no lamp in a strong current of explosive gas is safe unless protected by a tin shield.”

[Illustration]

If such is the case, Mr. Garforth seems to have struck the key-note when, in the recent paper read before the Midland Institute of Mining and Civil Engineers, and which we have now before us, he says:  “It would seem from the foregoing remarks that in any existing safety-lamp where one qualification is increased another is proportionately reduced; so it is doubtful whether all the necessary requirements of sensitiveness, resistance to strong currents, satisfactory light, self-extinction, perfect combustion, etc., can ever be combined in one lamp.”