3393. Scott, R. S., and Wheatley, J. March 3. Bell and gong signals; mechanical telegraphs.- Signalling-apparatus of the audible and visual type for use in mines comprises, in combination, two dials (" banksman " and "onsetter") each having two pointers, one pointer of each pair being operable independently of the other for a predetermined number of steps, after which the second pointer becoms independently operable to complete the signal. The pointers are retained at a given signal until the signal is complied with, and means are provided for resetting the pointers at zero on starting the winding-engine. An additional dial may be employed with separate pointers corresponding to the different levels in the mine, to indicate from which level a signal is received. Pointers 4, 5 are carried by spindles 4<a>, 5<a>, and pointers 4<b>, 5<b> are carried by sleeves loosely mounted on the spindles. The spindles carry ratchetwheels 8<a>, 9<a>, and the sleeves have ratchet-wheels 8, 9. Each pair of ratchet-wheels has a single operating-pawl 10, 10<a> normally out of engagement, as shown, and a single detent 21, 21a. The ratchet-wheels are so mutilated that one only is engaged by the actuating-pawl for a predetermined number of steps. Projections 24, 25 carried by the ratchets then engage one another, so that one ratchet is moved by the other into such a position that subsequent signalling-impulses move only the second ratchet. Thus, when one pointer has moved a predetermined distance, further impulses complete the signal with the other pointer. The pawl 10 is operated by a wire 11<b> and lever 11. The pawl 10<a> is operated through a lever 11<a> by any one of a series of wires (two shown) corresponding to the levels from which the signals are sent. Pios 14, 14<a>, carried by the levers 11, 11<a> and projecting through slots 15, 15<a>, serve to give audible signals on bells 16, 16<a>, which may be different in tone. To return the pointers to zero when a signal is complied with, the detents 21, 21<a> are connected by links 20, 20<a> and bars 26, 26<a> to a slidable member 27, which, when moved to the right, Fig. 2, by a rod 31, raises the detents. The rod 31 has an end piece 32 provided with a slot having an horizontal portion 33 ending in a vertical portion 34. A pin 35 carried by a rod 36 engages in this slot. When the rod 36 moves inwards, the rod 31 falls, the pin 35 entering the vertical slot 34. Subsequent outward movement of the rod 36 moves the rod 31, raising the detents. A projection 32<1> then rides up an inclined surface 32<2>, allowing the rod 31 to return the detents to the engaging position. The rod 36 is connected to a lever 37 held in the outward position by a catch 41 connected to the signalling-wire so as to be released when a signalling-impulse is given. The rod 36 is then moved inwards by a weight. The outward movement is given by a projection 40 carried by a disk attached to the winding-drum (not shown), moving a sliding member 39 connected to the lever 37 by a link 38. To prevent operation of the releasing-lever when the cage is in motion, an arm 55 is held in the path of the lever by a weight 61 during the motion, but is held out of the way when the winding is completed, by a quadrant 57 which engages one of two shoes 58a. The quadrant 57 operates in conjunction with an indicator of any suitable construction for showing the position of the cage in the shaft. The level from which a signal is given may be indicated by one of a number of pointers 45<a> corresponding to the levels. The pointers are held by catches 46<b> interconnected so that each indication cancels the preceding one. The catches are also connected by a link 50 to the detent 21<a>, so that the level indication is cancelled when a signal is cancelled by the winding-drum. Provision may be made for operating the release mechanism by hand. According to the Provisional Specification, both pointers of the "onsetter" dial move together for a predetermined number of steps.