Gambar halaman
PDF
ePub

WEDGE

CONDUCTOR

Flerated Institution of Mining Engineers

Transactions 1890-91.

VOL. II, PLATE XXXI

To illustrate Mr. John Yates paper on "An Electrical Safety Apparatus for Cages."

[blocks in formation]

END OF CAGE

[merged small][ocr errors]
[ocr errors]

A

SECTION of Wedges, showing projections which are arranged spirally

PLAN.

FIG. 6.

PLAN

CONDUCTOR

FIG. 7.

to withdraw these appliances and trust to good ropes well inspected several times a day. He was sure many of H.M.'s Inspectors of Mines would, with their extensive experience, support him in his statement.

Mr. YATES said that for a given amount of work the length of time that a battery would run without attention depends chiefly upon the capacity of the cells, and of course they could have any size they pleased, so that if it was desired to run the battery for three or four days without attention all that was necessary was to have the cells sufficiently large. Besides the Daniell battery there were many others that gave a constant current; for instance, the Bunsen, the bichromate, and a modified form of the Leclanché, the last of which will run without attention for two or three weeks. As regards not knowing when the battery would go wrong it was the easiest thing in the world to attach an indicator, which would at once show by inspection how the current was. The reason electrical signals, etc., sometimes failed was that a Leclanché battery was used which, being intermittent, very often failed; but there were other batteries in the market which would give a constant current without the least trouble. With reference to the apparatus coming into action by "jogging," they would of course allow for a margin of safety. Nobody would think of using a fiftypound magnet to lift at sixty pounds weight.

The PRESIDENT said it was a useful apparatus to bring before the members, but its effect had not yet been practically tested. The author said it had been brought before the public for the first time to-day, and therefore they could not judge of its merits until a practical trial took place. He therefore proposed that a vote of thanks be given to Mr. Yates for his interesting paper.

The proposal was received with acclamation.

The following report on the effect of the fumes of roburite and tonite was then read-the chemical portion of the report by Dr. P. Phillips Bedson, and the remainder by the Secretary :

AN INVESTIGATION AS TO WHETHER THE FUMES PRO

DUCED FROM THE USE OF ROBURITE AND TONITE

IN COAL MINES ARE INJURIOUS TO HEALTH.

REPORT OF THE COMMITTEE OF THE DURHAM COAL OWNERS' ASSOCIATION AND OF THE DURHAM MINERS' ASSOCIATION.

Complaints having been made by the workmen at various collieries that the fumes produced by roburite and tonite were injurious to their health, the matter received the attention of a Committee of the Durham Coal Owners' Association, who suggested that the question should be investigated by the North of England Institute of Mining and Mechanical Engineers.

The matter was accordingly brought before the Explosives Committee of that Institute, but that body considered that it would not be justified in interfering in any way in a dispute between employers and employed as to the use of any particular explosive, or in applying the funds of the Institute for the purpose. The Committee, however, stated that individual members would be glad to serve on any Committee which might be appointed by the Coal Owners' Association.

A general meeting of the Durham Coal Owners' Association was held on September 16th, 1889, to further consider the question, when the following resolution was agreed to:

"That a Committee be appointed by the Durham Coal Owners' Association, consisting of Messrs. A. L. Steavenson, W. Lishman, George May, M. W. Parrington, W. Armstrong, Jun., F. S. Panton, W. O. Wood, and T. Lishman, with Messrs. Bell and Willis (H.M. Inspectors of Mines), W. Crawford, J. Forman, John Wilson, W. H. Patterson, and four workmen, to investigate the question as to whether the fumes produced from the use of roburite and tonite in coal mines are injurious to health, with power to call in experts.”

This proposal was submitted to the Miners' Association, and agreed to by them, and the Committee was formed. Mr. Thomas Bell, H.M. Inspector of Mines, was appointed Chairman of the Committee, Professor P. P. Bedson and Drs. Drummond and Hume professional advisers, and Mr. M. Walton Brown, engineer.

Arrangements were made for experiments with the explosives which were the subject of the enquiry, the first series being made at Elemore Colliery in the presence

« SebelumnyaLanjutkan »