NOVEL TELEPHONY.

Star (Christchurch), Issue 7505, 12 September 1902, Page 2

NOVEL TELEPHONY.

♦ BY RAYS 0L ELECTRIC LIGHT. The Armstrong-Orling apparatus for telephoning through the ground or air is not the latest marvel of its class. Particulars have come from Berlin of suc-\ cessful experiments made there by Herr Ruhmer in telephoning by means of the rays of electric light. A distance of about four miles was covered, between a 'steamboat and a small island, and the clearness and loudness of the transmitted conversations are said to have struck everybody present at the test. An electric searchlight or flashlight is used-* as the transmitter. The words of the spoken message are carried into the flashlight lantern, passed through the flame, and the sound vibrations, carriedonwards %vith the powerful rays, so modify the hum of an electric arc lamp that it produces sounds like the human voice. The kernel of the discovery lies in a small piece of selenium used for the attraction of the vibratory rays into the large electric telephone receiver. Unlike the ArmstrongOrling invention, the Ruhmer system is not regarded as an advantage over the ordinary telephones for private use, but Herr Ruhmer claims that his telephone will be of inestimable service on board warships, where powerful searchlights are always ready for use. The trials of the instrument are to be continued between two fixed' land stations, and it is hoped to render possible, a conversation over 00 to 25 miles - by means of large reflectors of one to two metres diameter.