When Was the Fax Machine Invented?

Early cultures used drums and smoke signals to send messages. At the battle of Thermopylae, Greeks used mirrors to reflect the sun's rays and send signals. The Pony Express, while hardly instantaneous, was an early attempt to quickly send detailed information over long distances. But the telegraph really revolutionized communications, bringing the lightning-quick characteristics of electricity into play.

Scientists made great advances in the study of electricity in the 18th century, opening the way for the telegraph. In 1833, Germans Carl Friedrich Gauss and Wilhelm Weber built a working telegraph line that stretched for nearly a mile through the city of Gottingen. It wasn't long before William Cooke and Charles Wheatstone put the first practical telegraph into use in 1837. It used five needles that pointed to alphabet letters on the receiving end. Being an operator, therefore, required no great skill; only that the receiver write down the letters as they arrived.

This new timeliness would lead Scotsman Alexander Bain to wonder about sending not just signals but also images over the wires. Bain, a clockmaker, used his expertise to design and patent the basic concepts involved in the modern fax machine.

His idea, which became known as the "chemical telegraph," used the electric signals generated by a telegraph operator. The signals would pass through a type of paper that was soaked in a chemical. The signal caused the chemical to evaporate, leaving a long or short mark of Morse code. The marks allowed for much faster transmission and led him to create punched-hole tapes that allowed automated transmissions and reception.

An innovative technician, Bain invented the basic concept of a fax machine — an electric printing telegraph — when he patented the idea on May 27, 1843, decades before the telephone was patented and when the telegraph was only about 10 years old.

The process Bain used relied on electrochemistry and mechanics, which he mastered during his days as an instrument and clockmaker. Bain saw that the telegraphs of the day were slowed by simple mechanics. He also noted that the invention relied on electrical impulses, which he thought could be harnessed in a way that would create visual messages, speeding the process.

The chemical telegraph Bain invented, which would later be modified to become the first fax machine, at first simply sent "long" and "short" lines, which a telegraph operator could interpret quickly. The process was a success and the electrochemical process it used was a major leap forward for future fax technology.

Bain later applied the chemical telegraph idea to sending images. To send rudimentary pictures, Bain made a copy of the picture in copper and then discarded everything except the actual lines of the picture he wanted to send.

His process next used a pair of pendulums, synchronized at a distance by an electromagnet. He fitted the pendulum with a contact beneath it and swung it over the copper picture. Each time the contact touched the copper image, it would send an electrical impulse racing over the wire to the identical synchronized pendulum swinging over some chemically treated paper. The chemical in the paper darkened when touched by the energized pendulum. Both the sending picture and the receiving paper moved beneath each pendulum by 1 millimeter following each pendulum swing, resulting in a "scan" of the original and a copy printed on the other end, which eventually resulted in the copper image from the sending pendulum being duplicated on the paper.

Bain used a solution of nitrate ammonia and prussiate of potash to treat the paper that received the picture. When touched by the electrical impulse, the solution decomposed leaving a bluish stain. This created the first fax pages.

Following Bain's achievements, a group of inventors put the fax machine through many revisions before reaching its modern form. Giovanni Caselli created the pantelegraph around 1865 to use between Paris and Lyon, France. Building on Bain's ideas, Caselli's tall, cast-iron machine sent thousands of faxes each year.

Caselli's customers would write their message on a thin sheet of tin using a non-conductive ink. The operator would then place the tin on a curved metal plate, scan it with a needle, and send it to another pendulum-operated machine in the other city. Because of the non-conductive ink used to write the message, the receiving end would get an inverse reproduction of the sheet.

In 1903, Arthur Korn achieved the first photoelectric scanning fax machine network that linked Berlin, London and Paris by 1910. His method represented a step beyond Bain's contact scanning. Using the light-sensitive element selenium, Korn's machine could convert the various tones of a scanned image into different electric currents.

His work remained the standard for decades and paved the way for the Associated Press to begin a photo wire service that could send news photographs around the world. Korn would also invent a commercial picture transmitter that used radio waves instead of wires to send pictures across the Atlantic Ocean.

The French engineer Edouard Belin also invented a process that could send photos. He would first chemically treat a photo, giving it an uneven contour based on its light and dark shades. A needle scanner picked up these contours and converted them into varying electric currents, which could be sent to another machine. His continuous work made the machines smaller, faster and more reliable. He also found ways to encrypt fax transmissions for security reasons.

And then, in 1947, Alexander Muirhead demonstrated a modern fax machine incorporating a rotating drum scanner that became very successful.

Modern fax machines incorporate many improvements from previous versions, but the premise remains the same. The sender places an original on an electronic scanning bed where an electric "eye" looks at the paper and records the image, whether it be a complicated "picture" or simple text. The scanner then digitizes the image, turning it into a series of 1s and 0s that it can transmit over phone lines or the Internet.

On the receiving end, a computer processor re-assembles the image from the digital information and prints it out, either to paper or onto a computer screen. Instead of a rotating drum, modern fax machines use a photo sensor to "look" at the paper it's copying and sending. The sensor tells the difference between dark and light areas, which tells a computer processor how to reproduce the image at a distant location by encoding the information. The encoding makes it possible to send it along a phone line or over the Internet. At the receiving fax machine, the machine reads the encoded information and reassembles the image.

Modern fax machines come in many variations regarding speed, capacity, and resolution. Some work as stand-alone and others work in conjunction with computers. Still others are multi-function, working as copy machines and fax machines that send to other traditional fax machines or e-mail images to other computers.