GOWER-BELL TELEPHONE


In 1882 the Gower-Bell telephone became the GPO's standard set with 20,000 sets ordered.  There were two types of Gower-Bell instruments used by the British Post Office.  The first pattern used tubes for receiving speech (although some were later retrofitted with Bell receivers) and the second pattern which had a smaller case and only used Bell receivers for speech reception.

The telephone wiring was on the rear of the instrument and consisted of un-insulated wire, stapled to the wood.

The first pattern Gower-Bell telephone remained the Post Office choice for many years, and was continuously developed.  By 1886 it had become known as the Universal Telephone, so-called because it could be adapted for use under practically any conditions likely to be met with in Post Office service.

It is probable that the speaking tubes on some telephones were replaced after the Bell patents had expired (1891).  The telephone still retained the Gower Transmitter, with mouthpiece, but the receiver and speaking tubes had given way to a pair of Bell receivers.

The Gower-Bell company called the instrument the "Gower-Bell Loud-speaking Telephone".

Gower-Bell telephones were supplied worldwide, but all the Gower-Bell telephones produced for the GPO were clearly marked on the front of the case with an enamel plate.

The Gower-Bell telephone superseded the Crossley (Made by Blakey and Emmott) which was the Post Offices first telephone.


 

These telephones were used on permanent current system exchanges.

Click here for an explanation of how the phone worked

Click here for the Permanent Current System


First Pattern

This telephone, made by the Gower-Bell company, used a rather large receiver mechanism, which was invented by Frederick Gower.  It consisted of a very large magnet which made it more powerful than other makes, but was too heavy to be held to the ear.  Because of this it was fitted inside the wall cabinet and connected to two listening tubes.

The casing was of wood, measuring 520mm x 40mm x 200mm and weighed 5.86kg.
 
The transmitter which is the fitted to the cabinet cover, below the push button, is of the Pencil type.  This Gower transmitter is a variation on the Hughes carbon pencil microphone (invested May 1878), but consists of eight carbon pencils held in place by nine carbon blocks.  These are arranged in a star formation and connected to two copper strips, fixed to a pine board of 9" x 5" x 1/8".  This forms two groups of pencils in series with each group of four pencils which are in parallel.  Eight pencils were chosen because if less than eight were used, then noise could be heard as the pencils moved against the contact blocks.

A thin membrane covered the transmitter and this itself was sometimes covered with a wooden sheet that had slots and carvings in it to allow the sound through.

An induction coil with resistances of 0.5ohms (primary) and secondary of 250ohms (secondary) was fitted.

There are two automatic prong hook switches, on each side of the telephone, in which the ear-pieces of the flexible tubes are placed when not in use.  The right-hand one serves to break the local microphone circuit, the left-hand lever is the usual bell and telephone automatic.

At the top of the telephone is a press button for calling the exchange.

The incoming calling signal was a trembler bell which was rung by a battery at the subscriber's premises under the control of a relay operated by a signalling current received from the exchange.  The relay was fitted inside the telephone.  A feature of this system of working which has a modern sound was that when an operator rang the subscriber's bell she could hear the interruption in current caused by the trembler bell contact, a forerunner of ringing tone.  The relay resistance would be 100ohms.

One key disadvantage when using this telephone was that the design of the instrument required the user to remove and hold both tubes while speaking.  This also operated the automatic hook switches which signalled the exchange, thus leaving no hands free for writing.

There were a number of changes made to the phone and this is self evident by changes to the circuits and terminal layout.  On some telephones the labels were marked: BC, ZE, L and C, the six terminal model was marked BC, L, Z, ZC, Bell and Bell, whilst the eight terminal model was marked 1 to 8.

The telephone also changed when the transmitter cover was replaced with a thicker wooden plate, which had a white coloured Porcelain mouthpiece fixed in the centre.  This helped concentrate speech onto the transmitter mechanism fitted underneath.  The Consolidated Telephone Company made many like this.

Some later telephones were retrofitted with a Hunnings type transmitter.

The white labels fitted by the terminals were made of Ivorine.

Many early telephones were privately bought and connected between buildings, up to 14 miles apart (see advert).

In the original Patent, the line is shown as a single wire with an earth return, which was the normal way to connect at the time.  But due to induction from the multitude of overhead wires at the time, telephones using an earth return were extremely noisy.  The GPO diagrams only show two wire connectivity and this was the best way to stop induction at the time.

Click here for the Gower-Bell Patent (1880)

Click here for a Gower-Bell company advert


First Pattern Circuit Arrangements

Original Type and Six Terminal Type
Leclanche Batteries (Porous-pot form) must be used, unless the circuit's exceptionally long and underground or is very busy.  In such cases authority may be obtained to use 6-block Agglomerate Batteries for speaking.

Two cells must be used for speaking and two for local circuits.

Current required for Relays, 16 milliamperes.
Current required for Bells, 20 milliamperes.

Separate Bells or Relays are in all cases to be treated as separate Instruments.

The notes above are general for all the arragements mentioned below but excluding the eight terminal type.
 

Ordinary Type (with 4 terminals)

Ordinary with Bell
This was used on direct circuits not exceeding 200 ohms resistance.

This telephone has a four Terminals, a Relay and an integral  Bell.

Note the 4 terminals and the bell gong

 

The transmitter is located under the black plate

 

Internal view - the press button has been removed

 

Transmitter pencils

 


Six Terminal type

The six terminal telephone comes in two variations; "Old Form" and "New Form" and can be easily identified by the terminal layout.  On the Old Form, the terminals are blocked in threes, one block to the left and other block to the right of the telephone, all at the bottom of the backboard.  It also has three internal terminals.  The New Form has a four internal terminals and six terminals in a straight line, on the bottom of the backboard. 

There is a relay these telephones and the bell mechanism has been removed, so an external bell would have been supplied.

Old Form, six terminal telephone (Internal view)

 

New Form, six terminal telephone (External view)

 

New Form, six terminal telephone (Internal view)
Components are - Induction Coil (left back) - Receiver (centre) and Relay (front right)

 

Old Form with Relay
This was used on circuits which exceed 200 ohms resistance or which have Intermediate offices upon them.

 

New Form in Simple arrangement
Used on direct circuits not exceeding 200 ohms resistance.  The Bell is separate from the Telephone. No Relay is fitted in this arrangement.

 

New Form with Relay
This was used on Circuits which exceed 200 ohms resistance, or which have Intermediate Offices upon them.  A Relay is fitted which operates the external bell.

 

New Form for Exchange working
The Relay was adjusted with a "bias" sufficient to prevent its responding to the permanent current from the 5-Cell Daniell Battery. A Resistance Block should be inserted in the Relay circuit to reduce the permanent current to between18 and 20 milliamperes.

Between ZE and C are connected the two Leclanche cells required for the microphone.  Between EC and ZE five Daniell cells.  When the left-hand lever is down this battery is permanently connected to line. This constitutes the peculiarity of the system, as it is worked on the closed circuit system, a battery current always passing through the line when the instrument is not in use.  No earth return was used on this instrument, with double or metallic circuits being almost exclusively employed, and these were absolutely necessary, owing to the fact that the lines are run in close proximity to single-wire telegraph circuits, the induction from which on single-wire telephone lines rendered the voice nearly or quite inaudible.

 

Eight Terminal type
This was called the "Universal Telephone" as the internal connections were so arranged to provide for use in any ordinary situation.  The information here is from 1886 and all the diagrams show the use of a Gower Receiver.

No alteration of internal connections was required, but when a Relay was placed in the telephone case the coil ends would have been connected to the two right-hand screw studs, the base-plate to the fourth screw-stud (counting from the left), to which one end of the Receiver coils was also connected, and the contact block to the disconnected wire.  When a Relay is not used the two right-hand screw studs would to be connected together by a wire.

Leclanche Batteries (Porous-pot form) were used, unless the circuit was exceptionally long and underground, or is very busy.  In such cases authority would have been obtained to use 6-block Agglomerate Leclanche Batteries for speaking.

Two cells were used for speaking and two for local circuits.

Current required for Relays, 16 milliamperes.
Current required
for Bells, 20 milliamperes.

Separate Bells or Relays were in all cases treated as separate Instruments.

The telephone is fitted with six internal terminals and eight terminals, at the bottom of the backboard, which are numbered 1 to 8, from left to right.

The notes above are general for all the situations mentioned below.

8 terminal type with Gower Receiver

 

8 terminal type, retrofitted with Bell Receivers

In the circuit diagrams below the component locations are:-
Induction coil - Upper left.
Press Button - Upper centre.
Relay - Upper right.
Transmitter - Upper far right.
Gower Receiver - Centre.
Switch hooks - Centre left and right.
 

Simple Use
Used on direct circuits not exceeding 200 ohms resistance.  This telephone contains no relay.

The Bell is separate from the Telephone.

 

With Relay
Used on circuits which exceed 200 ohms resistance, or which have Intermediate Offices connected to them.

 

For Exchange Working
The Relay was adjusted with a "bias" sufficient to prevent its responding to the permanent current from the 5-cell Daniell Battery. A Resistance Block would be the inserted in the Relay circuit to reduce the permanent current to between18 and 20 milliamperes.


Exchange "Bias" working With Augmenting Battery

This system was required only when two subscribers desired to be connected (through the exchange) for communicating independent of the exchange.  The augmenting Battery, which is provided at each telephone, enables each to gain the attention of the other without calling the exchange.  This is principally applicable to cases where a subscriber having two distinct lines wished to be connected through at night.

The Relay was adjusted with a "bias" sufficient to prevent it responding to the permanent current from the 5 cell Daniell Battery.  A resistance would be inserted in the relay circuit to reduce the permanent current to between 18mA and 20mA.


 

Telephone at Intermediate Office
This shows the connections of the Telephone at an Intermediate Office on an Exchange Circuit where an Exchange Intermediate Switch is used.

 

All the information above was taken GPO Telegraph Apparatus Connections and Circuits instruction (Dated 1886).

 


Second Pattern Circuit Arrangements

The second pattern was considerably smaller than the first pattern, measuring 7 inches by 5 inches and projecting 6 inches.  The diaphragm is stained black.  The great objection to the china mouth-piece arrangement, used on the 1st pattern, lies in the fact that moisture is condensed upon it and when the telephone is much used most unpleasant odours are present.  So the china mouthpiece was removed and the telephone reverted back to it's original look.  The fixing heads for the transmitter were deliberately left showing on the transmitter tablet in an attempt to stop users from using the plate as a surface to write upon.

Second pattern Gower-Bell telephone made by the
Consolidated Telephone Construction and Maintenance Company Limited

The internal connections of the Post Office telephone are shown at the bottom of this page.  The transmitter is connected to two flanges upon the inside of the case. A screw passes through the flange on either side; thus joining the microphone to the connections on the back board of the instrument.

In this instrument the two Bell receivers are shown joined up in parallel.  The induction coil is fitted beneath the case, and formerly had a resistance of 0.5ohms and 150ohms respectively for primary and secondary. A coil having from 0.9ohms to 1.2ohms and 25ohms is now used (Coil, Induction No.1).  The instrument is fitted with eight external terminals, which precisely correspond with the eight terminals fitted to the first pattern Gower-Bell telephone.  The two central terminals are connected to the lines. From terminal 4 the current passes to the end of the lever button, along it to the left switch lever through the upper contact to terminal 1; from terminal 5 to the centre of the right switch lever, through the upper contact to 3. Thus the bell must be joined between 1 and 3. When the receivers are raised the left switch-arm joins them up, and the right switch-arm joins up the microphone battery, which is connected between 5 and 6. Terminal 7 is used for the ringing battery, which is joined up in series with the micro-phone battery, which is joined up in series with the microphone battery, which unites with it.

It will be seen on the circuit diagram that two terminals are joined together by a dotted line and they are marked "relay." Where a relay is not used these terminals connected together by means of a wire link, but when a relay is used this wire is removed, and the relay coil connected between them. The contacts of the relay are joined to the two wires marked "local."

The Post Office Telephone is also fitted with one receiver in some cases, and in this instrument the terminals also correspond with those of the Gower-Bell and Post Office "Telephone with double receivers". The adoption of this uniform system of connecting telephones up prevents any confusion when changing from one class of instrument to another. More recent telephones, fitted with Deckert transmitters, are joined up in exactly the same manner.

The Relay
A relay could be fitted in the telephone and when a relay was not installed, the terminals were connected together with a wire link.  The telephone at the subscriber's end is connected as shown in the diagram below. It will be seen that the battery employed consists of four cells, two of which are used also for the microphone and also as the local battery for the bell. The permanent current, usually about 7 milliamperes, is sent out by the four cells. The resistance of the indicator at the exchange is 1000ohms, hence for reasonable distances the resistance of the line is of little account. The current flows from the positive pole of the battery to terminal 1, through the relay and right hand switch-lever spring, through the back contact of the press-button to the A line, through the exchange indicator along the B line to terminal 5, and back to the negative pole of the battery.

It will thus be seen that the removal of the receiver from the switch-arms stops the permanent current, thus dropping the exchange indicator. This automatic signalling is one of the distinctive features of the Post Office system.

The relay at the subscriber's end is biassed against the permanent current passing through it, and in order to effect a ring the exchange clerk joins a battery to the line, which combines with the subscriber's battery, thus overcoming the bias upon the relay and closing the local circuit. The path of this local circuit is from the split of the battery to terminal 6, thence through the bell to terminal 8, to the contact screw of the relay, and through the tongue back to the negative pole of the battery.

Second pattern circuit diagram (Single receiver)
This shows a relay in the middle of the diagram
The terminals are numbered 1 to 8 from left to right
This circuit diagram can also be found in a 1898 telephone book.

 

Second pattern circuit diagram (Double receiver)
This shows no relay in the middle of the diagram, the relay being replaced by
a wire link, and the contact wires left ready for connection if a relay is required

 

All information on the second pattern telephone was taken from "The telephone system of the British Post Office, a practical handbook" by T.E. Herbert, dated 1901.
 

Operational Description
The microphone part of the transmitter is shown in Fig. 1, which represents the cover (partly raised to show the inside) which is placed over the apparatus on the base depicted in Fig. 2. The form of microphone is one originally devised by Gower, and known as the Gower-Bell transmitter, but its details have been modified and improved by the Post Office. It is, obviously, merely a special arrangement of Hughes' original microphone and consists of eight carbon cylinders or pencils mounted at the back of a thin pine-wood board 7inches long and 5inches wide. This board is mounted on a substantial wooden frame with small India-rubber pads interposed, for the purpose of intercepting vibrations to which the body of the instrument may be subjected. Two strips of thin copper, cc, each having an angular outline, are fixed on the lower side of the pine board, and on each of these are fastened four carbon buttons by means of little brass bolts passing through the centre of each button and through the diaphragm, and having little nuts on the lower or inner ends. The upper ends of these bolts protrude right through the board, so as to prevent it being used as a desk for writing purposes, for which its slope would otherwise make it very convenient, with, however, the danger of a probable dislocation of the carbon pencils underneath. There is also one large central carbon button fixed to the board in the same way. The carbon pencils are small cylinders with their ends turned down to fit loosely into circular holes in the buttons. They are arranged in the order shown, which may be described electrically as four in parallel and two in series. In all, there are sixteen microphonic contacts.

Fig. 1


Fig 2.

The copper strips c c are connected by wires to two substantial pieces of brass, B, of which one only is shown in Fig. 1. When the cover is placed in position on the base A A (Fig. 2), these blocks are screwed tightly to the angle-shaped pieces of brass b b, making good electrical contact. The other apparatus shown on the board consists of the levers L1 L2, for hanging up the receivers when not in use. This process of hanging up changes the contacts at the far ends of the levers from C1 to C2, and from C3 to C4, respectively.

The induction coil is at I, and there are eight terminal screws along the lower part of the board, which are left exposed when the cover is screwed down.

When a relay is not fitted a wire link is inserted at position S on fig. 3,

Fig. 3

The connections between the various parts are made by wires at the back of the board and are shown diagrammatically in Fig. 3, where the eight terminal screws at the bottom of the board are numbered for reference. The induction coil is represented by thin and thick spirals, and there is a press-button p for ringing-up, not shown in the other figures. The receivers R R are represented as hanging on the levers L1 L2, the cords attached to them consisting of twin wires whose other ends are connected to the screws on the board ; the screws themselves being so cross-connected that the two receivers are in parallel. The various fine straight lines represent the connecting wires, which are insulated from one another where they cross on the diagram.

When used for "simple" working on short lines whose resistance does not exceed 200 ohms, an ordinary trembling bell is attached to terminals 1 and 3, the line wires are attached to 4 and 5, and a split battery of Leclanché cells to 5, 6, and 7. In this case terminals 2 and 8 are not used. A wire is inserted in the position of the dotted line s. 

As shown the apparatus is ready to receive a "call."  A current coming by the line wire to 4, passes through p to the centre of lever L2, then through spring C4 and the wire s to terminal 1, through the bell back to terminal 3, then through spring C2, lever L1, to terminal 5, and back by the other line wire.  The bell is thus rung without the current passing through any other resistances but those of connecting wires and contacts.

The receivers R R being now lifted off the hooks and held to the ears, currents coming by the. line wires have a totally different course.  Arriving at terminal 4 a current passes through p to L2 as before, but now the contact is made with spring C3, instead of spring C4.  From C3 the current passes through the fine spiral of the induction coil, through the two receivers in parallel, then to L1, and back to line through terminal 5.  The telephonic message is therefore heard in the receivers.

For transmitting, the above circuit is acted on inductively by the primary spiral of the induction coil, and the induced currents take the path just traced out.  The primary spiral is in circuit with the battery and the microphone, which causes the sonorous pulsations in the battery current.  The battery current takes the following course:- Starting from terminal 6, it passes through the thick wire spiral of the induction coil to the block B2, thence through the microphone M to the block B1, through spring C1 to L1, and back to the battery by terminal 5.  Thus any change of resistance at M alters this current.  The requisite changes of resistance are brought about by simply talking near and towards the sloping board (Fig. 1), which carries on its under-side the sixteen microphonic contacts.

It is not necessary or advisable to shout or talk loudly to the board. Clear and distinct enunciation in an ordinary conversational tone of voice, with the speaker's mouth ten or twelve inches from the board, gives excellent results if the line be in good working order.

The circuit for ringing-up the exchange or the distant correspondent is very simple. When the button P is pressed, the spring p breaks contact on the left and makes contact with the knob A below. The current of the full battery starting from terminal 7 passes through A and p to terminal 4, away to the distant end and back to the battery by the other line through terminal 5.

We have described the courses of the various currents when the apparatus is used upon a simple telephone line. Without altering the internal connections it can also be used at an exchange or at an intermediate office, or at an ordinary subscriber's office. If necessary a relay can be inserted for ringing-up purposes.

It is therefore applicable to all the usual requirements of ordinary telephone work.

It only remains to be added that the Bell magneto receivers are of the double-pole pattern, very little modified from the Siemens and Halske's pattern.

Taken from "Electricity in the Service of Man" (dated 1897)

Additional comments
No introduction dates have yet to be found for this set, but it must have been after 1891 and before 1901 (the Bell receiver patent was extent in 1891 and Telephone No. 17 was available circa 1901).  The layout of the components and the circuit diagrams of the 2nd pattern telephone show that the backboard and components were used as the basis for Telephones No. 17, 19 and 21, the only differences being a new front case and a Deckert transmitter.

The circuit diagram for the 2nd Pattern, single receiver, model is the same as the Telephone No. 17 and the 2nd Pattern, double receiver, model is the same as the Telephone No. 19.
 


Non-GPO Use

And possibly on the Underground in London
In October 1888 the general manager was complaining about the efficiency of the old single needle telegraph instruments; messages were being misunderstood (or not taken at all) where signalmen were slow or otherwise lacked the necessary proficiency, especially at the Circle Line cabins where train intervals were so short that the busy staff didn’t have the time necessary to take messages correctly.  He asked that the instruments be replaced by telephones where no experience was necessary.  This must have been agreed to with some vigour. Instructions dated February 1889 explain that telephones had been provided ‘at each station and intermediate signal box’ between Aldgate and Notting Hill Gate and between Baker Street and Rickmansworth with the intention of improving communication about the working of trains; these had evidently entirely superseded the use of ‘speaking instruments’ which had been removed on these sections.  The instructions stated that each station had two telephone instruments, one connecting to the station or signal box ahead and the other to that on the other side.  Each telephone was equipped with two separate receivers, both of which were to be used (implying the use of Gower Bell instruments) and a single push button that rang the bell on the telephone at the other end of that circuit.  There was no exchange system or other interconnection between the instruments at that time. Annoyingly the notice is stated to supersede instructions dated December 1885, opening the distinct possibility that the telephones were installed then, with some modification in 1889, perhaps the removal of the telegraphs. (Taken from London Transport Telecommunications by M. Horne)

Japan
In 1893 telephone service began in the Osaka-Kobe area of Japan using two manual switching systems and 224 Gower-Bell telephone telephones.

South Africa
A Gower/Bell telephone was used with the opening of the first public telephone exchange in South Africa on 1st May 1882.

First pattern Gower-Bell telephone with cover removed


 


History
The Gower-Bell Telephone Company was formed in 1880.  The Gower-Bell telephone had first been manufactured by Messrs Scott and Wollaston with a licence issued to them from The Telephone Company Ltd.  Gower ultimately acquired the licence and formed the company, which supplied the Post Office with telephones.  The British Gower-Bell Telephone Company Limited was established on 25th March 1881 to acquire and extend the Gower-Bell Telephone Company and purchase the six patents upon which it was founded.  The Consolidated Telephone Construction and Maintenance Company Limited was then established on 9th April 1881.  It secured all of Gower's patent rights in the UK and abroad except for North America, France and countries served by the Oriental Telephone Company Limited.  It made arrangements with the United Telephone Company for the exclusive right to manufacture Bell, Edison and Gower patents for twenty years.

The British Science Museum have an instrument made by Scott and Wollaston, England, dated 1880.

See also:-
History of Gower-Bell

History of BPO Telephones


Pictures

First pattern with pencil type transmitter
This is the original 4 terminal type
 
First Pattern - 6 Terminal type
The original transmitter is below the mouthpiece
 
First Pattern - 8 Terminal type
Made by Scott and Wollaston
The porcelain mouthpiece was disliked as it tended to hold moisture which
caused a nasty smell!
 
Using a First Pattern Gower-Bell telephone
 
Second pattern Gower-Bell telephone
Made by the Consolidated Telephone Construction and Maintenance Company Limited
 
 
In the 2nd Pattern pictured below the receivers have been replaced by later types
Second pattern Gower-Bell telephone
Front view
 
Second pattern Gower-Bell telephone
Rear view
Note the nuts for the relay and induction coil fixings
 
Second pattern Gower-Bell telephone
Close up of the 8 terminals
 
Second pattern Gower-Bell telephone
Right hand switch hook
 
Second pattern Gower-Bell telephone
Left hand switch hook
 
Second pattern Gower-Bell telephone
Typical customer installation - Picture dated 1910
 
 
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Last revised: February 25, 2024

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