I am attempting to find a list of which mouthpieces are equivalent. The most common (different) threads are WE (7/8 inch) , Kellogg (15/16 inch) and Stromberg-Carlson (1 inch). Which (if any) of these would be compatible with North Elec., Monarch, Dean, Leich, American Electric, Williams, and any others you know of. Thanks.
I keep a cheat sheet for mouthpieces sizes and threads. Unfortunately some brands use multiple sizes, especially on the older phones.(pre 1905?) For instance, I have 2 or 3 different American Electric thread sizes. Also, the AE mouthpiece is very close in size to the WE - you can use a AE mouthpiece in a WE, but not vise versa. Here's what I have on my cheat sheet - I have more, but they're not written down. I'll see if I can dig them up and add to the list later on.
WE 7/8 fine
Leich, Monarch, S.C. 1" course
Dean 7/8 course
Chicago 13/16 course
Kellogg 15/16 course
AE 13/16 fine
Connecticut 15/16 fine
Western Electric seems to fit Couch
I have a list. I am not having Much luck posting it.
I will try later.
I compiled my list over 20 years ago. I combined every list I could find. I did not edit any spellings or conflicting info.
The thread descriptions I have are:
AE Smaller than WE w/ coarser threads
IT inside thread threaded on the inside
KE 15/16 medium threads
SC 1" coarse threads
WE 7/8" Fine threads
There are 67 different line items on the list including the spelling variations and conflicting info..
Desk Telephones of the Bell System
by Lawrence A. Wolff D.D.S.
The mouthpiece of the early telephone was something that directed the person toward the transmitter.
The very early mouthpieces were made of the same material that housed the transmitting element. This was usually wood. As the transmitters became more sophisticated, the mouthpieces were constructed as separate units.
Black hard rubber or a composite material was used at first. After Bakelite was invented and became more popular, it replaced the former materials.
Some mouthpieces were also constructed of an aluminum alloy or brass. Most "solid back" transmitter mouthpieces can be placed into one of four different thread patterns.
For example, Western Electric used a 7/8 inch fine thread and Kellogg a 15/16 inch medium thread. These were mouthpieces with outside threads. This meant that they screwed into a transmitter with threads cut into the opening of the faceplate.
Manufacturers such as Sumter, Sampson, Connecticut and North utilized mouthpieces that were threaded on the inside.
Below is a chart of the interchangeable external thread mouthpieces:
will fit on Century, Augusta, Varney, Stanley, Monogram, Williams, Acme, Kusel< Leich (Fine), Wesco (Fine) Stromberg
will fit on Baird, American, Eureka, Leich (Coarse), Monarch, Wesco (Coarse), Bucum, U. E. Co.Kellogg
will fit on North, Dean, Modern, Manhattan, Couch, Ericsson (Coarse), Utica Fire Alarm, Voight Berger, Sumter, Swedish AmericanAutomatic
will fit on Chicago, Oxford, Sears Roebuck, Interstate, Wesco, Ericsson (Fine), Julius Andrea, Voight Berger (Fine), Standard, DeVeau, Montgomery Ward
Bakelite mouthpieces were also made available in colors. This may have been the introduction of colored telephones designed to match the decor of a room. The Bakelite mouthpieces have been found in Bakelite colors such as Brown, Red and Green, for example.
Because of the epidemics of tuberculosis, influenza and even the plagues, people began thinking of methods for providing a barrier protection against cross contamination that was thought to occur by sharing intimate objects. A number of mouthpieces became available to adapt to the transmitters of most telephones. These mouthpieces were made of glass or porcelain and could be sterilized by boiling in water. The clear glass mouthpieces were popular because it was believed that light killed the germs. One of the more desirable glass mouthpieces was the Red Cross . This was patented in 1910 and manufactured by the Red Cross Telephone Mouthpiece Co., in San Francisco. There were a number of different adaptors that first screwed into the transmitter, some plastic and some metal. One of the metal adaptors had crosses stamped into metal. This mouthpiece was marked "Pat By E & L May 3, 1910 Red Cross Germ Proof Glass Mouthpiece CO" or "Pat by E & L May 3, 1910 Red Cross Germ Proof Mouthpiece." The glass had four colored crosses on it, usually red.
Another popular glass mouthpiece was the Whispering or Whisper It design patented in 1916 . The "Whispering Telephone Mouthpiece" was manufactured by the S. & M. Electric Co., 466 Monadnock Block, Chicago. This mouthpiece had a metal adaptor that had metal fingers to grab the rim of glass around the base of the mouthpiece and a "bullet" shaped projection in the center. The venturi design allegedly intensified the sound waves so that one would not have to speak as loud. The glass was marked "Whispering Mouthpiece Pat Oct 10th 1916" or "Whisper-It Mouthpiece Made in U.S.A. Pat Oct. 10th 1916."
The Maxim Specialty Co., of New York, had a glass mouthpiece which was patented in 1913. This mouthpiece had no special appointments and was held by metal fingers onto a metal base. A piece of medicated gauze could be held between the glass and the adaptor. The glass was marked "Maxim NY".
The Flint Sanitary Mouthpiece Company of Boston, Massachusetts manufactured a mouthpiece that had a metal adaptor and either a glass or porcelain mouthpiece. This mouthpiece had markings in the glass or porcelain that read: "Flint Sanitary Mouthpiece Trade Mark Pat Applied For."
Some porcelain mouthpieces were fabricated entirely in porcelain. One type was marked "American Electric Chicago" and had a letter on it identifying the thread type. The porcelain mouthpieces were often used as advertising vehicles by businesses.
The American Electric glass mouthpiece manufactured by Burns was a glass mouthpiece that had a metal adaptor that sandwiched the glass mouthpiece between a flange and the transmitter faceplate. The metal "baffle" had a pair of slots in the center forming an "X." The Bums glass mouthpieces were made of clear crystal glass and were available for a number of telephone manufacturers.
Here is another version of the list with more detail:
Threads to Manufactures List
Western Electric mouthpieces (7/8" fine thread 27 tpi) fit; Century,
Augusta, Varney, Stanley, Monogram, Williams, Acme, Kusel< Leich (Fine),
Stromberg mouthpieces (1" 18 tpi) fit; Baird, American, Eureka, Leich
(Coarse), Monarch, Wesco (Coarse), Bucum, U. E. Co.
Kellogg mouthpieces (15/16" 18 tpi) fit; North, Dean, Modern, Manhattan,
Couch, Ericsson (Coarse), Utica Fire Alarm, Voight Berger, Swedish
Automatic mouthpieces fit; Chicago, Oxford, Sears Roebuck, Interstate,
Wesco, Ericsson (Fine), Julius Andrea, Voight Berger (Fine), Standard,
DeVeau, Montgomery Ward