Danger Signals.

Huntly Press and District Gazette, Volume 4, 30 July 1915, Page 3

Danger Signals.

RED IS THE MOST EFFECTIVE COLOUR. Red is the colour universally i used as a danger signal because ] it can be seen farther than any i colour. It is also the colour that “attracts attention,excites curi- i osity, and arouses to action,” as 1 William Churchill s id in an ad- i dress before the Illuminating En- ] gineering Society. Green the complementary of red, is seen almost as far as red, ; but green is the colour of which Nature makes lavish use, and therefore a green signal is less easily recognised that a r.-,d, because the former may easily be ] taken for a part of the background, while the latter always contasts vividly with the back- ; ground. So green has been used for a clear or a cautionary sign. At night especially red is used J as a danger signal, red lanterns being placed on torn up streets a and construction, red tail lights | being used for motor-cars, red j lamps to indicate fire exits in j theatres, factories, and hotels, t and more recently to mark dangerous parts of machinery, high-current wires and other " danger spots. In Mr Churchill’s address, as quoted by the “ Scientific Ameri- I can,” he gave the effective range of the several coloured lights recognised by the Railway Signal s Association under ordinary weather condition as follows : Red, three and a half miles : yellow, one to one and a half miles ; blue, half to threequarters of a mile; purple half to three-quarters |of a mile ;

lunar white, two to two and ; half miles. Red, no matter how distant never ceases to look red. This is not true of any other colour though a good green fairly approximates it.