SIEMENS & HALSKE
Berlin

MAGNETIC TELEPHONE of THE 1880's

A BRIEF HISTORY

Telephones of the Bell type were introduced into Europe in 1877 and these were used for early experimental connections. Basically Bell's set was simply an earphone which was used as a receiver and as a transmitter. The currents produced, however were very weak and the set was therefore less suitable as a transmitter. Some improvements were made in the years after 1876 by Thomas A. Edison, F. Blake and Werner von Siemens from Germany.

In 1878, the Swedish authorities most concerned, above all the Telegrafverket, showed little interest in the telephone. In Germany, on the other hand, they reacted more promptly and had copies of the Bell set ordered from Siemens and Halske in Berlin, one of the leading electrical engineering companies. To copy the Bell instrument was possible because Bell had not taken out any patents in Scandinavia or Germany. Some of these sets found their way to Sweden, to the Ericsson workshops for repair, and at the end of 1878 LME began to manufacture telephones using the Siemens and Halske Magnetic telephones as prototypes. Only about 400 of the LME version were made (1878-1880) because there was not a great demand for them.

The telephones shown were made in Germany by the Siemens and Halske Co. of Berlin in the early 1880's. This type of telephone was used chiefly in Germany and were exported to other countries including Australia. These two instruments were used in Tasmania and very few others survive today in Australia.

The following description is from a book called "THE TELEPHONE" by William Henry Preece, F.R.S. and Julius Maier, Ph.D., Published by Whittaker &. Co. London in 1889. Further notes and photographs are by the author and from Ron Knappen's Old Telephone Scrapbook, LM Ericsson 100 years and from other sources, all drawings redrawn by Ken Bushell.

DESCRIPTION.

On the horse-shoe magnet mm two steel polar pieces ss, are fastened by means of screws. The polar pieces carry the small oblong soft iron cores uu. which are wound with fine insulated copper wire. The horse-shoe magnet is joined to the plate ee by means of a screw q, which passes through the iron plate ee, through the wooden block i fixed to the centre of the wooden block. When, therefore the screw is tightened, the magnet is lowered, whilst it is raised by the opposite action of the screw. Two small boards hh press on either side against the two extremities of the magnet, and serve for the reception of wires rr which are connected to the convolutions of the two coils uu. The wires rr end in two screws fastened to either side of the block i, and the line wires start from these screws.

An iron stirrup gg for the suspension of the instrument is fastened to the plate ee. (These are only on sets used as wall units)

The whole mechanism is placed in a cylindrical tube of sheet iron cc (Fig 2) in such a manner that ee forms the foundation plate of the apparatus. The tube carries a top piece bb, and is above b closed in the interior by means of a round piece of sheet iron. The apparatus terminates in a conical mouthpiece aa of polished wood, in the centre of which is a round opening lined with brass. The distance of the magnet from the membrane is regulated by means of the screw q, an arrangement which has been adopted in a number of other telephones.

The Siemens' instruments differ from Bell's latest pattern only in the form of the magnet which it employs. The straight uni-polar magnet has been replaced by one of the shape of a horseshoe and also the iron membrane is larger and stronger than that of the Bell instrument.

CALLING.

The call is effected by a small whistle or reed which is blown before the diaphragm of the transmitter, and produces a shrill tone in the receiver more than sufficient for the purpose.          This whistle is attached to the wooden earpiece by small piece of cord as shown. (Fig. 3). The whistle (Fig.4) consists of a conical tube of hardened india-rubber, in the interior of which an angular metallic piece ww is fastened by means of screws. A vibrating reed b is fixed at the one end to the piece ww, and free to vibrate at the upper end. The lower part of the angle ww is perforated, and in the perforation plays a rod h provided with a small clapper.

On blowing into the whistle, which is fastened to the top of the apparatus as in (Fig 3) sound like that of a penny-trumpet is produced: the clapper which touches the iron membrane by it's up and down strokes strengthens the vibrations of the latter, so that a shrill loud tone in the receiver is the result. Care that the whistle is removed from the earpiece was necessary to avoid damage to the ear.

Another method used for calling was a small handle which when turned vibrated the diaphragm to cause a similar sound to the above.

This is a very efficient form of telephone receiver and is quite powerful enough to be used as a transmitter. These instruments were used for point to point communications and were used as a receiver and transmitter (Fig. 6) which meant changing from listening to talking.

This was a rather expensive instrument owing to the numerous parts and materials employed. One of the main objections to doubling these telephones was the costliness of good horseshoe magnets, which were not easy to make. Later telephones incorporated two units as well as electric bells (Fig. 7)

Does anyone know what the serial numbers on the base of the instrument mean?  Maybe they can be accurately dated from these numbers as the Ericsson telephones can be. Let me know please.

For comments or questions email to Ken Bushell

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