1. Electromechanical Age (1840-1940)
The discovery of ways to harness electricity was the key advance made during this
period. Knowledge and information could now be converted into electrical impulses. The
beginnings of telecommunication
Voltaic Battery
Telegraph
Telephone and Radio
Voltaic Battery
Alessandro Volta invented the voltaic pile which is considered to be the first source of
stored electricity in the 8th Century.
The battery made by Volta is credited as the first electrochemical cell. It consists of two
electrodes: one made of zinc, the other of copper. The electrolyte is sulfuric acid or a
brine mixture of salt and water. The electrolyte exists in the form 2H+ and SO4 2-. The
zinc, which is higher than both copper and hydrogen in the electrochemical series,
reacts with the negatively charged sulphate. ( SO4 ) The positively charged hydrogen
bubbles start depositing around the copper and take away some of its electrons. This
makes the zinc rod the negative electrode and the copper rod the positive electrode.
Telegraph
Samuel F.J. Morse invented the first magnetic telegraph in the year 1832 and made an
experiment version in 1815.
Telephone and Radio
The first successful bi-directional transmission of clear speech by Bell and Watson was
made on 10 March 1876 when Bell spoke into his device, “Mr. Watson, come here, I
want to see you.” and Watson answered. Bell used Gray's liquid transmitter design [9] in
his famous 10 March 1876 experiment, but avoided describing the liquid transmitter in
his public demonstrations. The liquid transmitter had the problem that waves formed on
the surface of the liquid, resulting in interference.
Marchese Guglielmo Marconi [guʎe:lmo mar'ko:ni] (25 April 1874 - 20 July 1937) was
an Italian inventor, best known for his development of a radiotelegraph system, which
served as the foundation for the establishment of numerous affiliated companies

2. worldwide. He shared the 1909 Nobel Prize in Physics with Karl Ferdinand Braun, "in
recognition of their contributions to the development of wireless telegraphy". [1] Later in
life, Marconi was an active Italian Fascist[2] and an apologist for their ideology (such as
the attack by Italian forces in Ethiopia).
During his early years, Marconi had an interest in science and electricity. One of the
scientific developments during this era came from Heinrich Hertz, who, beginning in
1888, demonstrated that one could produce and detect electromagnetic radiation—now
generally known as "radio waves", at the time more commonly called "Hertzian waves"
or "aetheric waves". Hertz's death in 1894 brought published reviews of his earlier
discoveries, and a renewed interest on the part of Marconi. He was permitted to briefly
study the subject under Augusto Righi, a University of Bologna physicist who had done
research on Hertz's work.
Electromechanical Computing
Tabulating machine
Comptometer
Comptograph
Punch Cards
1853
Pehr and Advard Scheutz complete their tabulating Machine, capable of processing
fifteen-digit numbers, printing out results and rounding off to eight digits.
1885
A Comptometer is a type of mechanical (or electro-mechanical) adding machine. The
comptometer was the first adding device to be driven solely by the action of pressing
keys, which are arranged in an array of vertical and horizontal columns.
"Comptometer" is a trade name of the Felt and Tarrant Manufacturing Company of Chicago
(later the Comptometer Corporation, and then Victor Comptometer Corporation), and after
1961 was licensed to Sumlock-Comptometer of Great Britain. It is widely used as a generic
name for the class of device. The original design was patented in 1887 by Dorr Felt, a U.S.
citizen.
1889
Felt’s Comptograph, containing built-in printer, is intoduced

3. Punched Cards
A punch card or punched card (or punchcard or Hollerith card or IBM card), is a piece of
stiff paper that contains digital information represented by the presence or absence of holes in
predefined positions. Now almost an obsolete recording medium, punched cards were widely
used throughout the 19th century for controlling textile looms and in the late 19th and early 20th
century for operating fairground organs and related instruments. It was used through the 20th
century in unit record machines for input, processing, and data storage. Early digital computers
used punched cards as the primary medium for input of both computer programs and data, with
offline data entrykey punch machines. Some voting machines use punched cards.
The company which became IBM was founded in 1896 as the Tabulating Machine Company[6]
by Herman Hollerith, in Broome County, New York (Endicott, New York, Where it still
maintains very limited operations). It was incorporated as Computing Tabulating Recording
Corporation (CTR) on June 16, 1911, and was listed on the New York Stock Exchange in 1916.
IBM adopted its current name in 1924, when it became a Fortune 500 company.
1893
The Millionaire, the first efficeint four-function calculator invented by Otto shweiger, a
Swiss Engineer.
1906
Vacuum tube was developed by Lee De Forest which provide electricity controlled
switch. In electronics, a vacuum tube, electron tube (in North America), thermionic
valve, or just valve (elsewhere, especially in Britain) is a device used to amplify, switch,
otherwise modify, or create an electrical signal by controlling the movement of electrons
in a low-pressure space. Some special function vacuum tubes are filled with low-
pressure gas: these are so-called soft valves (or tubes), as distinct from the hard
vacuum type which have the internal gas pressure reduced as far as possible. Almost
all depend on the thermal emission of electrons, hence thermionic.