334,264. Reyrolle & Co., Ltd., A., Linstow, F. N., and Anderson, W. June 1, 1929. Selective distant control and signalling systems; twoposition indicators; transparency indicators.-In selective indicating mechanism, indicators are arranged around the circumference of a circle and are adapted to be engaged successively by a movable member of a rotary actuator, means being provided for operating the actuator in each position of engagement whereby the movable member sets each indicator in accordance with the condition to be indicated. As shown in Figs. 1 and 2, a panel A is provided with a series of windows A' behind which are located rotatable indicators C carried by a frame B. The panel A and frame B form a chamber lighted by lamps E. Each indicator consisting of a disc of glass is secured to a spindle D<2> provided at its rear end with a crank F and pin F<1>. Indications are given by comparing the position of a rod A<2> mounted in a ring A<1> in each window with the position of a bar C<2> painted on the front of the disc C. The bar C<2> and rod A<2> are preferably painted in contrasting colours. In a modification the indicator consists of a tube of glass which is slotted to receive a flat extension of the indicator spindle, the end of the extension acting as the indicator bar, and the window having a glass front with a narrow bar painted thereon. The rotation of each indicator is effected by the engagement of the pin F' with a movable member of the actuator and springs G are provided to retain the indicator in the position to which it is set. The actuator, shown in Figs. 4 and 5, comprises a bracket J rotatably mounted on a spindle H and carrying at one end two coils K, K<1> for operation on an armature L which can be moved against the action of springs M, from the central position shown, to one of two operative positions depending upon the coils which is energized. The other end of the bracket is provided with a slotted plate N to which is pivoted a slotted plate 0, the plates N, O being of the form shown so that as the actuator rotates in the direction indicated by the arrow first the wide part. of the slot N<1> and then the wide part of the slot O<2> engage the pin F<1> of the indicator. The plate 0 is connected to the armature L by links P, P<1> whereby movement of the armature effects a corresponding movement of the plate O about its pivot O<1>. The energizing circuits of the coils K, K<1> are arranged so that as the actuator is rotated the coils are de-energized prior to the movement of the actuator to a position of engagement, whereby the indicator, when the pin F<1> is engaged by the member 0, takes up a neutral position as indicated in Fig. 4<a>. The two operative positions are those in which the bar C<2> and rod A<2> are in line and at right angles, one position corresponding to the energization of the coil K and the other corresponding to the energization of the coil K<1> The coils are energized through slip rings R, R', R<2>, carried by the shaft H. The actuator is preferably controlled by a rotary selector mounted on or geared to the shaft H and adapted to control the association of the actuator circuits with the apparatus corresponding to a selected indicator. The. indicating mechanism may be used with a remote control system of the kind described in Specification 307,379 the actuator being mounted on the shaft of the selector at the control station and the substation selector being arranged to associate the actuator coils K, K<1> with the apparatus at the substation corresponding to the selected indicator so that one or other of the coils may be operated to set the selected indicator in accordance with the condition of the apparatus. The indicating mechanism may also be employed with a remote control system having the arrangements described in Specification 334,263. Specification 307,379 also is referred to.