SIGNALS FOR MINES.

Otago Witness, Issue 1341, 11 August 1877, Page 3

SIGNALS FOR MINES.

Some time ago the Government offered a reward of £100 for the beat apparatus for signalling in mines, and they appointed a Board to examine and determine the merits of the various inventions that might be submitted. The Board has just completed its labours, having examined no less than fifty-seven inventions. They 'first reduced this number 'to nine, and then to three. Briefly stated, the three inventions may be described as follows : — The first consisted of sliding signal boards with iron connections and fixed index finger ; the second of a fixed dial with revolving index finger and wire connections ; and the third of revolving dials with stationary index finger and water connections. The first is the iuvention of Mr J. Tangey, of Sandhurst ; the second that of Mr Jas. E. Ccttew, of Melbourne ; and the third that of the Hon. John Woods, M.L.A. It will be necessary, in the first instance, to explain the difficulties to be overcome, and what is required in order to supply all the required signals used in large mines. There are several well-known signals in constant use in the large mines. The following is the code in general use : — There are, in the first case, aa many separate signals as there are levels. Supposing there are twelve levels there must be on the indicating dials or boards as many separate numbers as will represent

these several levels. When the alarmbell is sounded, the look-out man, above or below, first signals the level speaking or spoken to. He then sends or receive? the order. The orders are : — Timber wanted, manager wanted, cage down, men down, timber down, laths down, water rising, quartz up, cage up, mon up, mullock up, timber up, laths up. It will be seen on slight reflection that when the connections by which these signals are worked are very long, the inevitable tendency will be for the wire or rod to stretch when tension is applied. Any slackness, therefore, in the wire, rod, or other connection, immediately produces irregularity, and a disordered connection will, when worked, indicate almost any order except that which has been indicated by the sender.

The object, therefore, is to secure simplicity, accuracy, and the prevention of variations generally caused by the tension of long connections. The Board made a series of careful experiments with the three inventions they thought worthy the cost of being practically tested, at the Great Extended Hustler's Reef, Sandhurst.

We may, at the outset, omit any lengthened mention of Mr Tangey's invention, as that was found, after long experiment, to be decidedly inferior in practical results to the apparatus invented by Mr James E. Cottew, and to whom the Board recommend that the prize of £100 should be given. This consists of an ordinary revolving dial and fixed fingerindicator. The dial and its appendage are fixed in grooved slides in the enginehouse. The connections are made' of wire, and they extend from one dial to another, each level being provided with a dial. The connections are kept taut, and are thereby made invariable in their working by the wire connections being conveyed over pulleys to the dial in the engine-house. As the dial and its metal roller depend from the wire connections, the wires are always kept taut by the tendency of the dial to slide down the grooves in which it is fixed towards the ground. This apparatus has been tried almost continuously for four months, and during that time it has worked efficiently and easily. It was found that during the four months the machine has been at work, it has only varied^one-eigth of an inch, which does not in any way affect the accuracy of the signal sent. — Melbourne Leader.