In 1800, Alessandro Volta invented the voltaic pile, providing a continuous current of electricity for experimentation. This became a source of a low-voltage current that could be used to produce more distinct effects, and which was far less limited than the momentary discharge of an electrostatic machine, which with Leyden jars were the only previously known human-made sources of electricity. Another very early experiment in electrical telegraphy was an "electrochemical telegraph" created by the German physician, anatomist and inventor Samuel Thomas von Sömmering in 1809, based on an earlier 1804 design by Spanish polymath and scientist Francisco Salva Campillo. Both their designs employed multiple wires (up to 35) to represent almost all Latin letters and numerals. Thus, messages could be conveyed electrically up to a few kilometers (in von Sömmering's design), with each of the telegraph receiver's wires immersed in a separate glass tube of acid. An electric current was sequentially applied by the sender through the various wires representing each letter of a message; at the recipient's end, the currents electrolysed the acid in the tubes in sequence, releasing streams of hydrogen bubbles next to each associated letter or numeral. The telegraph receiver's operator would watch the bubbles and could then record the transmitted message. This is in contrast to later telegraphs that used a single wire (with ground return). Hans Christian Ørsted discovered in 1820 that an electric current produces a magnetic field that will deflect a compass needle. In the same year Johann Schweigger invented the galvanometer, with a coil of wire around a compass, that could be used as a sensitive indicator for an electric current.M. (10 December 2014). Schweigger Multiplier – 1820. Retrieved 7 February 2018, from https://nationalmaglab.org/education/magnet-academy/history-of-electricity-magnetism/museum/schweigger-multiplier Also that year, André-Marie Ampère suggested that telegraphy could be achieved by placing small magnets under the ends of a set of wires, one pair of wires for each letter of the alphabet. He was apparently unaware of Schweigger's invention at the time, which would have made his system much more sensitive. In 1825, Peter Barlow tried Ampère's idea but only got it to work over and declared it impractical. In 1830 William Ritchie improved on Ampère's design by placing the magnetic needles inside a coil of wire connected to each pair of conductors. He successfully demonstrated it, showing the feasibility of the electromagnetic telegraph, but only within a lecture hall.Fahie, pp. 302–306 In 1825, William Sturgeon invented the electromagnet, with a single winding of uninsulated wire on a piece of varnished iron, which increased the magnetic force produced by electric current. Joseph Henry improved it in 1828 by placing several windings of insulated wire around the bar, creating a much more powerful electromagnet which could operate a telegraph through the high resistance of long telegraph wires. During his tenure at The Albany Academy from 1826 to 1832, Henry first demonstrated the theory of the 'magnetic telegraph' by ringing a bell through of wire strung around the room in 1831.
In 1800, Alessandro Volta invented the voltaic pile, providing a continuous current of electricity for experimentation. This became a source of a low-voltage current that could be used to produce more distinct effects, and which was far less limited than the momentary discharge of an electrostatic machine, which with Leyden jars were the only previously known human-made sources of electricity. Another very early experiment in electrical telegraphy was an "electrochemical telegraph" created by the German physician, anatomist and inventor Samuel Thomas von Sömmering in 1809, based on an earlier 1804 design by Spanish polymath and scientist Francisco Salva Campillo. Both their designs employed multiple wires (up to 35) to represent almost all Latin letters and numerals. Thus, messages could be conveyed electrically up to a few kilometers (in von Sömmering's design), with each of the telegraph receiver's wires immersed in a separate glass tube of acid. An electric current was sequentially applied by the sender through the various wires representing each letter of a message; at the recipient's end, the currents electrolysed the acid in the tubes in sequence, releasing streams of hydrogen bubbles next to each associated letter or numeral. The telegraph receiver's operator would watch the bubbles and could then record the transmitted message. This is in contrast to later telegraphs that used a single wire (with ground return). Hans Christian Ørsted discovered in 1820 that an electric current produces a magnetic field that will deflect a compass needle. In the same year Johann Schweigger invented the galvanometer, with a coil of wire around a compass, that could be used as a sensitive indicator for an electric current.M. (10 December 2014). Schweigger Multiplier – 1820. Retrieved 7 February 2018, from https://nationalmaglab.org/education/magnet-academy/history-of-electricity-magnetism/museum/schweigger-multiplier Also that year, André-Marie Ampère suggested that telegraphy could be achieved by placing small magnets under the ends of a set of wires, one pair of wires for each letter of the alphabet. He was apparently unaware of Schweigger's invention at the time, which would have made his system much more sensitive. In 1825, Peter Barlow tried Ampère's idea but only got it to work over and declared it impractical. In 1830 William Ritchie improved on Ampère's design by placing the magnetic needles inside a coil of wire connected to each pair of conductors. He successfully d?emonstrated it, showing the feasibility of the electromagnetic telegraph, but only within a lecture hall.Fahie, pp. 302–306 In 1825, William Sturgeon invented the electromagnet, with a single winding of uninsulated wire on a piece of varnished iron, which increased the magnetic force produced by electric current. Joseph Henry improved it in 1828 by placing several windings of insulated wire around the bar, creating a much more powerful electromagnet which could operate a telegraph through the high resistance of long telegraph wires. During his tenure at The Albany Academy from 1826 to 1832, Henry first demonstrated the theory of the 'magnetic telegraph' by ringing a bell through of wire strung around the room in 1831.