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grip the bow of the bucket or cage, thus keeping them in position in case the rope breaks ; the doors also 
instantly close. 
As regards the invention itself, there is considerable merit and ingenuity in it, and Mr. Gherardin is 
deserving of praise. Practically, however, I do not consider it would be a success. We have the self-acting 
doors in use already for years, and as for the hooks, they are not to be compared with Middleton’s or many 
others that I have seen. The hooks will only act when the rope breaks from over-winding, whereas 
Middleton’s will disconnect, and thus not only prevent the poppet-heads, but the engine also, from being 
forced out of position, and at the same time hold the cage and keep it from falling. On the whole, 
therefore, I cannot recommend it for use, as we have many appliances already which, for safety, are far 
preferable to it. 
Although the Inspector’s report is unfavorable to the use of the contrivance, 
I have given it a place here, believing that it is only by giving publicity to the failures 
as well as to the successes of inventors that an approach to perfectness in mining 
appliances will ultimately he attained. 
Hart’s Patent Safety Cage. 
In introducing his cage to notice, Mr. Hart remarks :— 
In constructing a safety cage that will prove master of the important work it has to perform in case of 
accident to the rope, or from over-winding, it is absolutely necessary to employ a superior gripping power, or 
resisting force, than would be given out by a falling cage; and this can only be done by bringing into imme¬ 
diate action a proportionate amount of holding power to the weight of a cage and its contents. Besides this 
superior power, it must bo instantaneous in its action, as a falling weight not only gathers velocity, but 
increases in weight; and, and if allowed to pass through a space, cannot he easily arrested, if nt all. Thus 
it will be seen that any invention which claims' to be reliable, must possess four essential points, namely:— 
1st, Immediate action ; 2nd, Certainty of action ; 3rd, A gripping power more than equal to the weight it 
has to sustain; and 4th, Simplicity of construction together with direct action. Without these features it is 
useless trying to secure satisfactory results, or to prevent the sad accidents which have of late been so 
frequent, and which have resulted in the loss of valuable lives, saying nothing about the loss of property. 
My cage is made of boiler-plate, with a roof sufficiently strong to carry its own weight, together with 
its load. Through the roof passes a suspension bar, which is attached to the rope or chain at the upper 
end. This suspension bar is also attached to two levers, which act upon a joint or fulcrum ; the one lever 
going to the one side of the cage, and the other to the opposite side. Between the ends of these levers and 
the roof of the cage is fixed a strong spiral spring, which encircles the suspension bar. The other ends of 
the levers are connected to the gripping bars, which act upon radius arms working upon strong studs, 
secured at both ends; the one to side of cage, the other to a cover, which protects the radius bars. The 
gripping bars are in a G-feet cage, 4 feet long by 3 inches wide, and work upon the principle of a 
parallel rule. These gripping bars are notched like a ratchet; and, upon the rope breaking, or from over¬ 
winding, they are instantaneously brought against the skids, presenting 288 square inches of gripping 
power. There will also be a handle attached to suspension bar, so that when men are coming up, or going 
down, they will have command of the grippers, in case of accident to the rope. It will thus be seen that I 
have entirely dispensed with the usual cam-shaped grippers, which have failed to present a suflicient force 
equal to the weight they have had to contend against. Hence the accidents. My invention can be attached to 
any cage that has solid sides at a cost of from £15 upwards. A new cage completo, at from £25 upwards, 
according to weight and size. 
A trial of the above-mentioned cage was made recently at the mine of the 
Amherst United Quartz Mining Company, Amherst, and was witnessed by Mr. 
Inspector Trezise, who reports respecting it as follows : — 
In the first test the double-weighted truck had about 8 cwt. on. Detaching the rope, the cage 
dropped half an inch only. 
2nd test.—Tried the hook for over-winding with the same truck in cage as before. On slipping the 
rope, the grippers acted instantly. 
3rd test.—After the above tests I went in the cage with the patentee, the manager of the mine, and 
one of the workmen (four of us) to descend from the brace to the surface. When within 2 feet of 
the surface, I pulled on the detaching lever and disconnected the rope from the cage; the drop was not 
perceptible. 
I consider the above tests highly satisfactory, and in a good vertical shaft the cage cannot fail in 
the object for which it is designed, the gripping power being greater than in other cages at present in use. 
Section 8, clause 17, of the Regulation of Mines Act (see Synopsis, page 92), has been overlooked 
in the construction of the cage, as you will observe by a careful examination of tho plans. This was pointed 
out to the patentee (Mr. Hart), who lias taken steps, to comply with the above provision. When this is 
done I shall forward to the manager (Mr. Clark) a certificate that the cage has undergone the tests to my 
satisfaction. 
The model of the cage was also inspected by Mr. E. R. Meekison (Travelling 
Inspector of Mines and Machinery), who reported:— 
The model acted on every trial, and caught at once, and I am of opinion that, if kept in good order, 
in the event of the rope breaking, it would suspend the cage in the shaft, as it has an unusually large 
serrated gripping surface. The hook is of the description that allows the cage to fall away. In my 
