In the early 19th century, all of the essential components necessary to construct an electrical communication system had been discovered. The most important of these were the battery by Volta, the relationship between electric current and magnetism by Oersted, and the electromagnet by Henry. It now remained for someone to find a practical method to combine these technologies into a working communication system.
Some commercial electrical communications systems existed in Europe as early as the 1830s. A classic example of this is the English "Needle Telegraph". The needle telegraph required two or more lines to form a complete circuit. It was also relatively slow and the design of the transmitting and receiving instruments was complex. Something simple and efficient was needed.
The Morse system of telegraphy was invented by Samuel Finley Breese Morse in the 1840s in the United States. "Morse Code" is essentially a simple way to represent the letters of the alphabet using patterns of long and short pulses. A unique pattern is assigned to each character of the alphabet, as well as to the ten numerals. These long and short pulses are translated into electrical signals by an operator using a telegraph key, and the electrical signals are translated back into the alphabetic characters by a skilled operator at the distant receiving instrument. It has also been acknowledged that Morse's partner Alfred Vail very likely assisted in the development of the code and the instruments used to transmit and receive it.
Morse telegraphy became the standard method of electrical communication in both the United States and Europe due to its simplicity and ability to work on inferior quality wires. In 1851, countries in Europe adopted a new code known as "continental" or "international" code. This new code was a modification of the original Morse. The new code eliminated the characters using spaced dots which were found to cause errors in transmission on undersea cables. The new code became the standard for all telegraph work except in North America where the original Morse was used on all landline circuits (except for undersea cable).
The applications of the Morse telegraph were many. The most well known of these to the general public was the commercial telegram service. The railroads were an early and enthusiastic user of the Morse system which improved the efficiency and safety of railroad operations manyfold. The Associated Press was originally an alliance of Morse telegraph services and operators dedicated to news dispatches. Industry found the telegraph indispensible for the transmission of business related communication including information on stocks and commodities. The American Civil War was the one of the first demonstrations of the military value of the telegraph in the control of troop deployment and intelligence. Even the flow of oil through pipelines was controlled by Morse telegraph.
In the 1920s automated teleprinter technology had become reliable enough to begin to replace the Morse operator. Manual landline telegraphy was slowly phased out until the 1960s when Western Union and the railroads discontinued use of their last Morse circuits. Morse continued to be used in Canada until the mid 1970s, and railroads in Mexico were still using the wire at least until 1990. A small but hardy group of retired telegraphers and telegraph enthusiasts continues to keep landline Morse alive in the US via a mode called "dial-up" telegraphy.
The study of manual telegraphy can be split into two major areas. The original application of the code was in what is referred to as "landline" telegraphy. Overhead wires or cable buried in the ground or in the ocean were used as a transmission line for the electromagnetic pulses. In the early 20th century, the Morse code was adapted to wireless transmission using radio waves. This became an extremely important commercial application of Morse code, particularly for communications with ships at sea. Eventually it was decided by international agreement that the "continental" code would be adopted for use in all radio communication. Thus telegraphy can be divided into its "landline" and "radio" applications.
Radiotelegraphy continues to be used commercially at the present time.
In the United States, it is confined to a few shore stations communicating
with ships at sea. This activity is expected to be gone in a few short
years. Radiotelegraphy continues to be used by several tens of thousands
of radio amateurs worldwide.
The "MORSE" Code And The Continental Code
The original "Morse" code used by Samuel Morse to allow letters to be sent as short electrical signals (dots) and long electrical signals (dashes) was also called the "American" Morse Code.
It was widely used throughout Europe and America in very early (mid 1800's) land-line communications and has continued to be used to the present in America for this form of telegraphic communication.
It was replaced in England in the 1800's by a somewhat similar code which eliminated the spaces and long dashes within letters that were found in many of the letters in the original Morse code. This new code was called the "Continental" or "International" Morse code and became the universal standard for European land-line communication and for radio telegraph communication.
Here is a list which shows the dot and dash equivalents of letters and numbers in the Morse code and the Continental code.
( DOT = * DASH = - LONG DASH = ---- )
CHARACTER: MORSE CODE CONTINENTAL CODE
A * - * -
B - * * * - * * *
C * * * - * - *
D - * * - * *
E * *
F * - * * * - *
G - - * - - *
H * * * * * * * *
I * * * *
J - * - * * - - -
K - * - - * -
L ---- * - * *
M - - - -
N - * - *
O * * - - -
P * * * * * * - - *
Q * * - * - - * -
R * * * * - *
S * * * * * *
T - -
U * * - * * -
V * * * - * * * -
W * - - * - -
X * - * * - * * -
Y * * * * - * - -
Z * * * * - - * *
1 * - - * * - - - -
2 * * - * * * * - - -
3 * * * - * * * * - -
4 * * * * - * * * * -
5 - - - * * * * *
6 * * * * * * - * * * *
7 - - * * - - * * *
8 - * * * * - - - * *
9 - * * - - - - - *
0 ------ - - - - -
Period * * - - * * * - * - * -
Comma * - * - - - * * - -
Question - * * - * * * - - * *
