The Bell System introduced the dial telephone in 1919 with Western Electric Company manufacturing the equipment used. In 1922 the Bell System introduced dial service to the large metropolitan area of New York.
The # 2 dial
To most of us, a Western Electric Type 2 -dial is characterized by a finger stop screwed to the outside of the case and a loud clickety clack sound made when dialing. However, the continual engineering updating by Western Electric presents a large group of differences.
The first obvious difference you will find in examination of these early dials is the marking on the finger stop. These markings consist of: 2AA, 2AB, 2AE, 2CB, 2EA, 2EB, 2HA, 2HB and unmarked. The first letter indicates the type of switch contacts mounted on the rear of the dial. The "A" type of contact was the most used since it was intended for use in telephones such as the candlesticks. This "A" type of contact has four screw terminals on the switch assembly. The "E" type of contact was the same contact assembly as the "A" type but with each of the five contact points brought out to a screw terminal. The "E" type was intended for use in telephone company trouble desks and repair stations. The "H" type of contact assembly was created for the new "French" style B (202) telephone introduced in 1928-1929. This contact style, used continuously by the Bell System until the mid 1950's, also had five screw terminals. The "C" type of contact was the same as the "A" type, and may have been used in coin collector applications. The "C" type dial was used on repairmen's hand test telephone sets. It is factory adjusted to run at 12 PPS rather than 10 PPS. This was intended to permit technicians to test dialing accuracy under more severe conditions than subscribers would experience using normal 10 PPS dials
The "C" type of dial differed from the "A" type of dial in that it had speed adjustment marks on the governor similar to the type 4 dial. The second letter on the finger stop indicates the style of the numbers and letters on the face of the dial. The letter "A" indicated numbers only on the dial face and was intended for use in rural areas with one central office. The letter "B" indicated numbers and letters on the dial face. It was intended for use in metropolitan areas which had many branch exchanges that were given names rather than numbers. The letter "E" also indicated numbers and letters but in a different arrangement from the "B" type. The "E" type was probably for party line use. The 2_E type has only the party letters "J, M, R, and W" located in the same holes (5, 6, 7 & 9) in which they would appear on a 2_B dial. These letters were probably selected for minimum chance of confusion when passed verbally to an operator. The #9 catalog illustrates this number plate for a #4 dial, which almost certainly would have matched what appeared on a #2 dial.
Occasionally a type 2 dial will be encountered which has been remarked by the Bell System. For example, 2AE dial restamped 2AXA or a 2AB restamped 2AXA, where the "X" indicates that the letter has been overstamped to obscure it, and a new letter stamped beside it. In addition, dials may be encountered which have been converted to different contact styles as, for example, the conversion of an "A" contact to an "E" contact.
The second most obvious difference observed is
the method in which Western Electric marked their name on the dial.
This marking consists of three types. The first type of marking is
"WESTERN ELECTRIC MADE IN USA PAT APP FOR" on the case external circumference.
The second type consists of marking "WESTERN ELECTRIC PAT IN USA AUG 13 12 AUG 24 15 DES MAY 7 18 SEP 13 21 MADE IN USA" on the case external circumference. This type appears to be the most common and also the best looking when mounted in an early telephone. The third type was the information of the second type but on the rear surface of the case, with a plain external case circumference. Therefore, the third type no longer had the information visible when mounted in a telephone.
If the dial is removed from the telephone and examined, it will be discovered that the type 1 case marking has two varieties. The earliest type is stamped "2A" on the back of the case near the governor flywheel. The other variety has no such stamp. These early types also have different governors, main shafts which hold the finger wheel, and case cut-outs for the switch pulse arm.
Other differences occur with internal parts. These part differences consist of the following: switch screw contact insulators (red, brown black, and layered red) four main shaft varieties, two purser spring varieties (one of which silenced the clickety. clack), two finger stop varieties (the type 3 being stronger) and two number plate supports.
During the 1930's many type 2 dials were modified by the Bell System so that they would fit in the type D 202 telephone. This modification consisted of changing the finger stop to a type which bolted to the inside of the dial case instead of to the outside. The dial face and support were also modified to accommodate the new finger stop. These dials modified and unmodified, were used well into the 1940's. The modified dials used the "H" type of contact assembly created for the B telephone introduced in 1928-1929.
The # 4 dial
To many of us, a Western Electric No. 4H dial is a converted No. 2 dial which still has the loud clickety-clack sound when dialed. The converted dial has had the old finger stop removed, the holes plugged and a new finger stop installed. However there is more to the No. 4 H dial than this simple description.
If the first thing you look for is those plugged holes, you will soon discover that not all 4 H dials have the plugged holes! The dials with the plugged holes are called "transitional' since they made the transition from the No. 2 dial to the No. 4 H dial. The 4 H dials without the plugged holes were regular production 4 H dials not conversions of the earlier type. The transitional types were converted to satisfy the demand until ample 4 H dials were available. This is typical of the Bell System philosophy of never throwing anything away, and of continually recycling equipment..
The 1930's saw the conversion of many No. 2 dials to the 4 H configuration. These converted 4 H dials can properly be referred to as "transitional" 4 H dials since they made the transition from the No. 2 dial to the No. 4 H dial. All of the No. 2 types and varieties mentioned before can be found in the transitional 4 H dials. Of course this does not include the finger stop varieties of the No. 2 dials since the finger stops were removed and replaced in the transition to the 4 H dial. The No. 2 dials were still being converted to transitional dials in 1939 when a hybrid "E' type of contact assembly using parts from the No. 2 switch assembly and the new 5 H contact assembly, just introduced into the Bell System, were used. Fitting the hybrid switch assembly required modification of the No. 2. This modification was similar to the elongated hole in the 5 H dial case. Transitional dials also exist with complete 5 H switch assemblies.
Examination of the differences in the regular production 4 H dials requires either partial disassembly or removal from the telephone. The first obvious difference which is observed is the method of painting the rear of the dial case. Up until this time all dial cases were copper plated over a steel base and painted black. However, the last type of 4 H dial did not depend on copper plating and painting for corrosion resistance. Instead the case was chemically treated and painting was only used to protect the screw threads. This chemical treatment gave the dial a gray color on the unpainted areas.
The most obvious difference which is observed in the 4 H painted case types is the method in which Western Electric marked their name on the dial. All marking is on the rear surface of the dial. This marking consists of two types. The earliest type of marking is "WESTERN ELECTRIC MADE IN USA PAT IN USA AUG 24 15 DES MAY 7 18 SEPT 13 21" on the rear surface of the case. This type used the following parts from the No. 2 dial: the main shaft, the governor gear bracket, and the governor speed adjusting screw. The second type of marking is "WESTERN ELECTRIC MADE IN USA PATENT 1151541 DES 52009 1390679" on the rear surface of the case. Apparently the only part used from the No. 2 dial is the governor speed adjusting screw.
The type 4 H chemically treated case had the following case marking: "WESTERN ELECTRIC MADE IN USA PATENT 1151541 DES 52009 1390679." This dial incorporated a new stronger main shaft, a new governor gear bracket, a governor with marks for adjusting the speed, a new stronger speed adjusting screw, and a new dial face support to accommodate the new finger stop. The composition of the "off center" switch actuator on the rear of the dial was changed from steel to brass. The switch contact assembly was largely unchanged from the 2 H type. Examination of the ends of the individual contacts in the contact assembly reveals that the earliest contacts are square cut and the latest are rounded on the ends. Those in between are a gradual transition from square to round. Generally, rounded cut contacts are either at the top or bottom of the contact stack on type 2 dials, and usually only on variety 3 of the Type 2 series. Transitional dials may have all rounded contacts if the assembly was replaced in total during the transition. Since the bottom two contacts (or the two contacts nearest the case edge) were added to the transitional dials during the transition, they are generally always rounded. Type 4 dials should have all contacts rounded (transitional types excepted).
Clearly the type 4 H dial was still basically a No. 2 with the incorporation of engineering improvements. This dial still had the clickety-clack sound when dialed. The only varieties the chemically treated case type 4 H dial is a slightly modified face support which was changed in 1937. This dial can also be found with an unmodified type 2 face support.
As an aside, in the mid 1930's the Bell System
converted from the type 132 dial face to the type 149 dial face also called
a number plate since the dial numbers were on the dial face. The
149 number plate had a kind of keyhole instead of a round hole for the
main shaft and was a better barrier against dirt. The 149 number
plate was constructed with a plastic protective layer- over the numbers
to protect against wear. A paper gasket was also installed under
the type 149 number plate to further prevent foreign material from entering