AN EXACT COPY OF A LETTER SENT TO THE BEESTON FACTORY
16th Feb 1951
Messsrs, Ericsson telephones Ltd
Beeston (Notts.) England
For the attention of Mr. R. C. Woods
We regret the long delay in answering your letter, but our expert on the subject, Mr. Hemming Johanason, was ill when it arrived and it was not until today that he was able to give his reply, which reads as follows.
The magneto instrument (fig. 117 in Pooles handbook) is the same as No. 375 in Ericsson’s
catalogue. It is “the Trade Mark” telephone, called the “Skeleton type” by the English telephone people. It was
constructed by L. M. Ericsson himself in 1884. Before the hand microtelephone
existed, the instrument was provided with an Ericsson “Spiral microphone” on a swinging arm and an ordinary hand set. From the
year 1890, however, all instruments of this kind had handmicros. It was introduced in England soon
after, and when the National Telephone Company in the year 1698 closed a contract with the Ericsson Company for a delivery of
100,000 telephone sets, a fairly big part of this quantity consisted of type 375 table sets.
As regards the handmicro, it was also constructed in the year 1884 with the spiral microphone as
sender and on the first samples an ordinary hand set as receiver. As these part improved the handmicro also improved, and from the
year 1890 these instruments had a granulated carbon microphone, with or without capsule and the small receiver with ringing
magnets. Fig. 89 in Poole’s book shows the polarized ringer in the type 375 table set. After the
introduction of Central Battery
and Automatic Telephones systems this type of table set was not practicable it is of course made exclusively for magneto systems
and the manufacturers had to turn over to more suitable types.
As regards other types of table set., it is of some interest to remark that the illustration 119 in Poole’s book refers to an instrument, also constructed in Stockholm by Ericssons (look at the side plate!). It was copied by i.a. Elektrisk Bureau in Oslo, from which factory a lot of them were delivered to the Glasgow Corporation. On account of the deliveries to the National Company Ericsson did not like to help their big opponent in Glasgow.
Concerning the battery ringing instrument, fig. 124 in
Poole’s book, it was constructed in Stockholm by Ericsson in the late 1890’s and principally used in telephone plants of
smaller extensions. A lot of them, of perhaps a little stronger make, were delivered to the G.P.O. in the years about 1900.
L M ERICSSON Library
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