Western Union Telegraph Company 100 Ohm Main line Sounder 15-C manufactured by the J.H. Bunnell & Co. Circa 1901
If you can provide further details such as where it was used, pictures, etc. of this item please me.
Here is what I know:
Mounting board: The bottom board used to hold all the components appears to have been painted a greenish color that did not show well in the pictures on this web page. The board is 8 1/2" wide by 7 1/2" deep. The bottom is a natural wood color with circular saw cuts used to recess the wiring. A copper plate nailed to the top front of the board is stamped with the numerals "31".
Sounder: The sounder is marked on the main lever J.H. Bunnell & Co, New York. U.S.A. which dates it to the beginning of the 1900's. The metal base of the sounder is marked "Ghegan patent July 16 1901". The Ghegan patent number for this sounder is 678,395 which expired in 1918. John J. Ghegan was a share holder in the J.H.Bunnell Company and later became president in 1903. The black wood base the sounder is mounted on has a metal tag nailed to it that states "W.U. Tel. Co. Main Line Sounder 15C 100 ohms". The black wood base measures 5-1/2 x 3 inches and is stamped 100 ohm Main line Sounder 15 - C on the outside edge. Between the base of the sounder and the terminals the black wood base is marked "W.U. Tel. Co. ". The bottom of the black wood base has an ink stamp that states "N.Y.R.S. 1334 Inspected".
A main line sounder was designed to attach directly to the live telegraph line without the use of a relay and were employed in lines longer than 15 miles.
Capacitor: The capacitor is marked "W.U. Tel. Co. Spark Killer 1-D Mfd by the Potter Co." The capacitor has an ink stamp that states ""W.U. Tel. Co. 01990 or 01890 inspected" On the side near the three terminals it states "1/4 MF +20" and next to that is ""1/4 MF".
Key: The key is stamped between the terminals with ""Legless key 2A W.U. Tel. Co.". The circuit closer arm is marked with "J.H. Bunnell & Co, New York. U.S.A.".
Connection block: Here I am referring to the rectangle box found in the top right corner and above the key. The lid on this box opens to reveal three terminals. The center terminal is not used. Under the cover is "W.U. Tel. Co." molded on the hinge side. While the clasp side states "Conn Block 78" or 7B. The cord below attaches to two of the terminals on this connection block .
Cord: The cord is a greenish color with cloth insulation. The end terminates into a 1/4" mono phono plug with "W.U. Tel. Co. 7B" stamped around the rim. This cord attaches to two of the terminals on the connection block described above.
As best as I can tell the item works as it should when I applied 6 volts to a connection at the bottom of one of the sounder coils and one of the key terminals. I have decided to leave the item in "as found" condition. Although it would look pretty with the brass and chrome parts polished.