It was recently stated in connexion with the signal station at Holyhead that messages sent by the thirty to forty candlepower electric light were visible at a distance of ten miles. A year or two ago a series of experiments were carried out between Germany and Holland, the result of which suggests that the range of the Holyhead light has been somewhat over-estimated. Io these experiments it was ascertained that one, two. and three candle-powers were visible to the naked eye one; two, and three miles re-cliter lights range of visibility did not increase in the sume ratio. Tt was necessary to use binoculars to see faintly a ten candle-power light only four miles away or a thirty candle power at five miles, The foregoing figures refer to green lights; red lights of the somme candle-power were visible at rather greater distances. White lights were less penetrating than green up to six candle-power, but higher power their ranz# visibility exceeded that of green lights, only eighteen candle-power being' required to carry five compared with thirty candle for green.
Text read from the printed page and cleaned; old type leaves the occasional error.