Special Features
A system of four lights are provided, arranged horizontal and equally speaced from each other, such that each quarter if a min shall be postively identified lamp no. 1 shall light continuously, lamp no. 2 will light from the 16th to the 60th sec, lamp no. 3 will light from the 31st to the 60th sec, lamp no. 4 will light from the 46th to the 60th sec