ROTARY SYNCHRONIZER 



'45 



is a circular opening, behind which is placed an incandescent lamp. 

 In front of this lamp, and immediately behind the dial-plate, is a 

 pivoted vertical aluminium swing-plate of the shape shown in the 



9TO 



BEARING FOR ALU 

 MINIUM SWING-PLATE 



3 INCHES 



Fio. 108. Mechanism of Visual Signal. 



lower part of Fig. 105. This plate is fitted with two coloured trans- 

 parent screens, a red and a green one, and is free to swing to one side 

 or the other.'so as to place one or other of the screens in front of the 



L 



