he and others had to do in the old days. They had now a cage to go up and down the shaft in; they would not care to put their leg through a loop and swing in the shaft with only a yard stick to guide them from bumping against the side; not many mining engineers would do that nowadays, but he got so accustomed to it in his apprenticeship days, that he would think no more of going down a pit 600 yards deep in that way, than he would of getting his breakfast. Use was second nature, but no doubt the mining engineers would prefer the present mode of getting down a pit to the old rough way. Again he thanked them for the toast, and he would give them this sentiment-"Success to our next merry meeting." It was arranged that the next meeting should be held in Birmingham in September, and he had no doubt that they would be received in as hospitable a manner as they were in Yorkshire, Nottinghamshire, and in Northumberland.

The PRESIDENT proposed "Her Majesty's Inspectors of Mines," to whom, he said, the mining engineers were indebted for much valuable assistance. This toast having been honoured,

Mr. WM. COCHRANE said they would all join very heartily in congratulating themselves, not only on having their Chairman as President of this Institution, but on having as their Chairman a friend and a venerable gentleman who had arrived at an age allotted to very few It was an honour to have such a friend and fellowworker, They could not separate without thanking their President for his valuable services, and congratulating him that his health and strength had enabled him to go through the labours of that day, and that at the end of the day they should find him so happy and contented. Might he be spared many years yet to be an example to them, and to remind them to be in their lives what he had been in his; and might they be able to show anything like the same health, strength, and vigour when they arrived at his age.

The PRESIDENT said he could only say how very much obliged he was to Mr. Cochrane for the sentiments he had expressed, and he hoped the morrow's proceedings would end as agreeably as the present day's had done. He might say this that if a person wanted to live long he must work hard when young, take it rather more quietly when he attained middle age, and when he came to fourscore years he must take it very easily. And during all that time he must cat and drink frugally, not living every day on great delicacies such as they had enjoyed that day, but having something which was quite plain and common. If that was done the digestion would not suffer, and there would be no occasion to take dinner pills after dinner, and the liver and other things would not get out of order. He would not detain them longer; he hoped he would be spared until the September meeting and many meetings after that, for he felt quite well and might almost say young; the only deficiency he felt was in his knees, which were growing very weak and feeble. If any mechanical engineer could supply him with a new pair he would be glad to have them.

The proceedings then terminated.

FEDERATED INSTITUTION OF MINING ENGINEERS.

GENERAL

MEETING,

HELD IN THE ROOMS OF THE INSTITUTION OF CIVIL ENGINEERS, 25, GREAT

GEORGE STREET, WESTMINSTER, MAY 29TH, 1891.

MR. T. W. EMBLETON, PRESIDENT, IN THE CHAIR.

Mr. YATES read the following paper on "An Electrical Safety Apparatus for Cages":

:

W W

VOL. II.-1890-91.

AN ELECTRICAL SAFETY APPARATUS FOR CAGES.

BY JOHN YATES.

Although great advances have been made in recent years in nearly every branch of mine engineering, we are no better off to-day for a reliable safety cage than we were twenty years ago. Engineers have either been unable to devise a good safety apparatus, or they have not given that attention to the matter which it deserves.

That it does deserve attention cannot be doubted in the face of the statistics contained in the reports of H.M. Inspectors of Mines. According to these reports, there were between the years 1880-1890 no less than 45 fatal accidents, resulting in 87 deaths, caused by the breaking of ropes and chains in shafts.

Forty-five fatal accidents in ten years is certainly a very serious state of things, but although this is a large number there is cause for sincere congratulation, that out of the millions of miners whose lives have at one time or other during the last ten years been hanging, so to speak, by a thread, so few have lost their lives by the breaking of that thread. The fact remains, however, that 87 lives have been lost through causes which are entirely preventible, for had the cages been provided with efficient safety appliances every life might have been saved. These figures should convince the most sceptical of the desirability of safety cages.

Engineers are well aware that many of these so-called safety cages have been brought forward from time to time, but have not found very much favour in this country, although on the Continent they are very generally applied.

Though their construction is faulty, they have been the means of saving numer. ous lives, and have perfectly justified their adoption and verified their claim to the name of safety cage.

The writer considers that their construction is faulty, and this is borne out by the evidence given before the late Commission appointed to investigate Accidents in Mines. In the reports issued by this Commission it will be found that many of the managers who had applied safety cages spoke very favourably of them, but that others raised objections to them, on the ground that they were apt, in quick winding, to come into action when not required, and that they did not invariably act when they should do. It was because of the objections thus raised that the Commissioners, although evidently desirous of advising the general adoption of safety cages, were compelled to admit that, after examining nearly all the safety cages introduced up to that date, "they were unable to come to the conclusion that any one of them was a trustworthy safeguard against accident."

The late Sir Warington Smyth, the President of the Commission, in referring to the safety cages which had so far been introduced, said that "they were apt in quick winding, when the rope surged or slacked, to come into action when not

required, and that this, along with the common dislike of trusting to a spring for setting it in action, militated against their general adoption by the coal trade."

That the safety cages which have so far been put before the public have not been an unqualified success is due to the fact that they rely upon springs to set the apparatus in action, and that something more than the mere breaking of the rope is requisite to let these springs act. The fracture of the rope is not in itself sufficient to actuate the apparatus-many of them require a release of tension or compression, whilst others depend upon the cage attaining a certain velocity.

Experience has shown that an apparatus which acts indirectly, through the medium of a spring or otherwise, is not to be relied upon.

What is wanted is an apparatus which will require nothing more to bring it into action than the breaking of the rope, and which will be entirely independent of everything but this.

For some time past the writer has been at work on this matter, and the result of his labour has been the invention of an apparatus which appears to promise perfect safety in case of breakage of the rope.

Before describing the invention, the conditions which a safety apparatus should fulfil may be stated as follow :

1.-It should never fail to act when required.

2.-It ought never to come into play except when the rope breaks.

3.-It should allow of being tested.

4.-It must be simple in construction and require little attention.

5.-It should in no way interfere with the ordinary work.

This is the standard to be attained by a good safety cage, and the manner in which this standard may be attained is to use the hauling rope as the means for conveying a current of electricity to four electro-magnets on the cage, each of the magnets sustaining a gripping cam. On the fracture of the rope and the breaking of the current, the cams would drop into play against the guides.

This is a general outline of the apparatus, the details of which will now be described.

The rope is, to all intents and purposes, the ordinary hauling rope, except that it has two insulated copper wires in the hemp core. It differs from the ordinary winding rope in no other respect, and thus, so far as winding is concerned, engineers have what is practically the ordinary rope. That such a rope can be made, and will transmit a current of electricity in a satisfactory manner, is beyond doubt, for a similar rope is now in use with the Armstrong electrical signalling apparatus-an apparatus for signalling between the engine house and the cage whilst in motion. This signalling apparatus has been applied at many of the collieries in the Durham district, and has been in daily work for some years. It has given every satisfaction. Messrs. Haggie, of Sunderland, who have the making of this apparatus, have kindly presented me with a piece of the rope used, and it is here for inspection.

A better test than what the rope has been subjected to could not be wished for, and the manner in which it has stood the trial of daily work for years should be sufficient to convince anyone that not the slightest difficulty is to be apprehended from the rope.

The copper wires of the rope are connected at the cage end to the electromagnets (Figs. 3 and 4, Plate XXXIII.), and at the drum end to two insulated copper rings on the drum axle, these rings being connected to the battery, as shown in Figs. 1 and 2, Plate XXXII.

The current goes down one wire and up the other, and is generated by a battery of a few cells, such as the Daniell, these giving a constant current, and requiring no attention except the adding of a few crystals of copper sulphate (CuSO4, 5H2O) at intervals. With a battery of this description a perfectly continuous current can be obtained without the slightest difficulty and without the least trouble.

The electro-magnets are of the horse-shoe form, these being the most suitable, such electro-magnets can be made to sustain a weight of 200 pounds per square inch of section. It will thus be seen that a comparatively small magnet may be made to support a great weight or pull, and electro-magnets have been made to sustain over two tons. Whilst speaking of the lifting power of magnets, it may be of interest to mention a rather novel use to which they have lately been put. They have recently been attached to cranes, and used for lifting masses of iron, instead of the ordinary lifting tackle.

The arrangement for gripping the guides consists of four levers (Figs. 3 and 4, Plate XXXIII.), cach lever working independently of the others. One end of these levers is so shaped as to form the gripping cam, and the other end is heavily weighted, also having a spiral spring attached, as shown. The weight and the spring tend to pull the long arm of the lever down, and thus throw the cam into contact with the guide. The electro-magnets are placed directly over these weights and support them, thus keeping the cams out of action.

Here attention must be called to the simplicity of this gripping apparatus, consisting as it does of only one lever. Instead of having a cumbrous, complicated arrangement of levers, bell cranks and springs, together with, in many instances, a special suspending frame-instead of all this there is a single lever, which cannot possibly get out of order, or jam.

Again, in some of the safety cages at present in use, there is a connection between the rope and the gripping levers; hence, when the rope breaks, the action of the apparatus is impeded, and might actually be prevented, by that part of the rope trailing behind the cage.

In the apparatus proposed, however, it will be seen that the action of the levers is free and entirely unimpeded-there is nothing to interfere with their action.

Another very important advantage of this arrangement, and one to which especial attention is directed, is, that there are in reality four distinct sets of safety apparatus, instead of the usual one, for as before remarked, each of the levers is complete