Germany erected in 1903 a fast flashing light on the island oi Helgoland in the North Sea. The system or principle employed is said to be entirely new. Not only that, but it was said to present absolutely insurmountable difficulties. The revolving light on Helgoland is not only the largest in the world, it is the most unique, for Germans claim that it never had a model.
They built upon the superiority of the Ger man reflector, with its exactly parabolic ground glass mirror or speculum, and the marvelous success. of the Helgoland fast-flashing light has justified itself. In these lines, for a long time, France was in the lead. The reflector invented by Schuckert, with its parabolic mirror, has earned a place by the side of the world's very best work. The bright fires feux iclairs— of the system, based upon a combination of Fresnel lenses and totally reflecting ring prisms, which were built by the French with marvelous skill and accuracy, blocked the way to the new lights. About the middle of the 90's German experts were sent to France by the German Imperial government for the express purpose of study ing flashlights. The experts stayed long enough to find out all that was best in the French system, aided thereto by the kindness of the scientific men of the republic. Before their return they were convinced that by means of two or more reflectors, erected upon a re flector with Schuckert's glass parabolic mirror, results equal to those of France could be pro duced.
Experiments were made in Nuremberg. They went far beyond what the most sanguine had believed possible. The revolving reflector of the German apparatus was fully equal to the Frenchman's revolving light. As soon as the experts had demonstrated their point, work was begun on a light reflector or projector equal to the largest ever used. It was to represent 30, 000,000 candlepower and to last no longer than one tenth of a second. The flashes must follow each other every five seconds. When the weather is favorable the beams go far beyond the central fires of light rays. On the first night that the new light was used, its peculiar, flashing beams were seen by people standing on the mole at Busum, a distance of 65 kilometers, or a trifle over 40 miles. The watchers in the lighthouse at Amrum, about the same distance, were able in unfavorable weather to see the same beams as they rapidly appeared and dis appeared. It was noted that the otherwise bluish-white light of the electric arc appeared red. Attempts, which are still in the stage of experimentation, are being made by means of radiography to ascertain position in fogs, and to determine direction and distances in fog by means of radio signals. The unreliability of sound waves in a medium like air, which is not of uniform density, and thus give rise to °silent zones,') add an element of uncertainty to all apparatus so far invented. See BUOY; ELECTRIC LIGHTING; FOG; LIGHTHOUSE; MEGA PHONE; SIREN; TOPOPHONE