The New Telegraphy.

Progress, Volume II, Issue 8, 1 June 1907, Page 285

The New Telegraphy.

The close of the past year saw the publication of a most important discovery which promises to revolutionize methods of telegraphy and telephony. The Poulsen wireless system was described in full in our notice of the inventor, Mr. Valdemar Poulsen, and of his colleague, Mr. P. O. Pedersen : and also the finished apparatus maintaining communication between this country and Denmark. The principle employed is that of using undamped electrical oscillations for the transmission of signals, the result being extreme economy of power over the longest distances, and a very high degree of tuning or selectivity. The source of the oscillating current is a simple electric arc adapted and arranged in circuit, as for producing the well known phenomenon of the " singing " arc.

The transmission and reception is, of course, a matter of resonance, and the degree of^fineness in tuning, obtained between one instrument and another without mutual influence occuring, is in practice represented by one per cent, difference in the respective wave lengths of their circuits. The communicating stations at Copenhagen and North Shields are about 350 miles apart, and a perfect interchange of messages is kept up continuously with a power of about 7kw. and masts aboat 100 ft. high. It is said that the inventor is now perfecting a similar system of wireless telephony, and we may expect to hear of something very startling and of the greatest value in this branch of electricity in the near future.