corner) is set. As it is set in the engraving, only the lodge bell rings.
Fig. 90.
§ 73. There are still two cases of electric bell and signal fitting, to which attention must be directed. The first is in the case of ships. Here all the connections can be made exactly as in a house, the only exception to be made being that the indicators must not be of the pendulum, or other easily displaced type; but either of the form shown at [Fig. 67] or [68], in which the electro-magnet has to lift a latch to release the fall or drop, against a pretty stiff spring. Besides being thus firmly locking, so as not to be affected by the ship's motion, all the wood work should be soaked in melted paraffin wax, the iron work japanned, and the brass work well lacquered, to protect all parts from damp. The second case requiring notice is that of lifts. Every well-appointed lift should be fitted with electric bells and
indicators. In the cab of the lift itself should be placed an electric bell, with as many double contact pushes and indicators as there are floors to be communicated with. At the top and at the bottom of the left shaft, as near to the landing side as possible, must be set two stout wooden blocks (oak, elm, or other non-perishable wood). From top to bottom of the shaft must then be stretched, in the same manner as a pianoforte is strung, on stout metal pins, with threading holes and square heads, as many No. 12 or 14 bare copper wires as there are floors or landings, and two more for the battery and return wire respectively. Care must be taken that these wires are strung perfectly parallel, and that they are stretched quite taut, but not strained, otherwise they will surely break. To the top of the cab, and in connection in the usual manner by wires with the bell and indicator (which, as in the case of ships, must be of the locking type, lest the jolts of the cab disturb their action) must be attached a number of spoonbill springs, which press against the naked wires running down the shaft. The shape of these springs (which should be of brass) at the part where they press against the bare wires, is similar to that of the spoon break of a bicycle. Some operators use rollers at the end of the spring instead of spoonbills, but these latter rub the wires and keep up good contact, while the rollers slip over the wires and do not keep them clean. By means of these springs, the current from the batteries, which are best placed either at the top of the lift itself, or in one of the adjacent rooms (never at the bottom of the shaft, owing to the damp which always reigns there),
can be taken off and directed where it is desired, precisely as if the batteries were in the cab itself. It is usual (though not obligatory) to use the two wires furthest from the landing as the go and return battery wires, and from these, through the other wires, all desired communication with the landings can be effected. To obtain this end, it will be necessary to furnish every landing with a double contact push and bell, and each bell and push must be connected up to the shaft wires in the following mode:—
A wire must be led from the lower contact spring of the double contact push, to the main battery carbon wire in the shaft. A second wire is led from the upper contact stop of the double contact push to the bell, and thence to the main battery zinc wire on the shaft. Lastly, a third wire is taken from the upper contact spring of the push and connected to that particular wire in the shaft which by means of the spoonbill springs connects the particular push and indicator in the cab, destined to correspond with it. It will be seen that with the exception of using the rubbing spoonbill springs and return wires in the shaft, this arrangement is similar to that illustrated at [Fig. 87].
