Jean-Antoine Nollet The first wireless Network

advertisement

The Telegraph:

The Victorian Internet

Jean-Antoine Nollet

The first wireless Network

Nollet’s Experiments

• As Abbot of the Grand Convent of the

Carthusians in Paris, Nollet decided to test his theory that electricity traveled far and fast.

Nollet’s Experiment

• On a spring day in 1746, Nollet sent 200 of his monks out in a line 1 mile long. Between each pair of monks was a 25-foot iron wire. Once the reverend fathers were properly aligned, Nollet hooked up a battery to the end of the line.

Nollet’s Experiment

• As the electric charge surged through the line of monks, all started swearing, contorting, or otherwise reacting simultaneously to the shock. The electrical signal had traveled nearly a mile and it appeared to have done so “instantly”.

Electricity and Nollet

To impress King Louis XV, Nollet discharged a

Leyden jar in front of at Versailles by sending current through a chain of 180 Royal Guards, causing them all to jump in the air together

Electrified Men

Women were suspected as being likely to arrest or deflect the longitudinal surge of the electricity. In one experimental line of electrified men, the current came repeatedly to a standstill at the same person, whose manhood came as a result into embarrassing question. His reputation was only restored when experiments on accredited castrati failed to show any difference in their conductivities. The maligned man had in fact been standing in a puddle which had discharged the current

Wireless Communication

Popular in the early 19th century was the heliograph, which was invented in 1810 by the

German mathematician Carl Friedrich Gauss.

The heliograph sported two mirrors that could be tilted by an operator to point in just the right direction.

The Occulting Telegraph

• Babbage entered the optical communications arena in 1851 with a plan for a light-flashing machine that he named the "occulting telegraph." This is how

Babbage described his device:

"I then, by means of a small piece of clockwork and a lamp, made a numerical system of occultation, by which any number might be transmitted to all those within sight of the source of light."

Heliographs in Practice

Upon receiving a description of Babbage's contraption, the U.S. Congress appropriated $5,000 -- a considerable sum at the time -- for occulting-telegraph experiments.

It's not clear what the outcome of the experiments was, but a several decades later the American army started using machines to transmit data across beams of light, most notably heliographs.

In 1886, Nelson Miles, the general perhaps best known for his capture of Geronimo, used a network of heliographs to transmit messages to his troops while fighting various Native American tribes. His network comprised 27 signaling stations in Arizona, placed 25 to

30 miles apart.

Miles Heliograph Network

Records from that time indicate that between May 1,

1886, and September 30, 1886, a total of 2,276 messages containing 80,012 words were transmitted over the network. The average speed of the system was reportedly 16 words per minute, or roughly 10 bits per second . Clearly, the technology rewarded those who could express themselves succinctly.

The Native Americans, of course, had their own opticaltransmission system, which dated back further still. Most likely, the data rates achieved with smoke signaling could have rivaled those of Miles's network.

The 18

th

Century and Beyond

It is hard to imagine what daily life must have been like two centuries ago, without radios, movies, telephones, or electricity. The streets in the larger cities were lit by candles. In New York, for example, a city ordinance had been in effect since 1697

. . . that the lights be hung out in the darke time of the moon within this citty, and for the use of the inhabitants; and that every 7th house doe hang out a lanthorn and a candle in it.

Mail was delivered by stagecoach in the United States, and by merchant vessels and mounted couriers throughout most of Europe. A letter or newspaper took only a few days to travel from London to Stockholm, and to get a piece of mail delivered within one of the larger cities took just hours. It was not unusual to extend a dinner invitation by regular mail in the morning, and to receive the response well in time to make the final preparations for that day.

The First Telegraphs

In September 1794, Abraham Niclas Edelcrantz, a Swedish nobleman and scholar, sits in his library in the center of Stockholm, in front of a large fireplace. He is reading

Gentleman's Magazine

Edelcrantz Learns of Chappe’s

Telegraph

The September 1794 issue of this journal contained a report on a new

French contraption that caught Edelcrantz's attention. This is, in part, what Edelcrantz read

. . . a method to acquaint people at a great distance, and in very little time, with whatever one pleased. This method is as follows: let persons be placed in several stations, at such distances from each other, that, by the help of a telescope, a man in one station may see a signal made by the next before him; he immediately repeats this signal, which is again repeated through all the intermediate stations. This, with considerable improvements, has been adopted by the French,and denominated a Telegraphe; and, from the utility of the invention,we doubt not but it will be soon introduced in this country. ( Britain )

The invention was attributed to Claude Chappe.

Chappe Semaphore Network

Early Experiments

Claude Chappe, born in 1763, Grandson of a French Baron, trained for the church. He lost his religious benefices in the wake of the

French revolution in 1783 and decided to work with his brothers on the problem of the optical telegraph.

Synchronized System

Early Chappe Experiments

The Synchronized System (1791)

“ The first telegraphic correspondence that we performed was done with two pendulum clocks, that were kept in perfect synchrony; the face of the clocks was divided into ten parts, each part designating a different numeral When the pointer of one clock passed over the number one wanted to indicate, a sound was made, announcing to the receiver that the number which also his pointer indicated at the moment that the sound was heard, was significant. By representing the words in a dictionary with successive numbers one could thus transmit any thought. ..." .

The Panel Telegraph

• The Panel Telegraph (1792)

• Rectangular wooden frame with five sliding panels that could be displayed or obscured via pulleys. A 5-bit binary code (32 combinations) was used . to this was developed and the

A system very similar eventually by the British

Swedes.

The Semaphore Telegraph

• Horizontal beam (called the "regulator") + two smaller wing beams (called the

"indicators"), could be varied in 45 degree increments.

Funding !!

• The National Assembly of France voted

6000 francs to Chappe to build the system. This was the first recorded use of the term telegraph = "far writing."

References to word Telegraph

"The capitals of distant nations might be united by chains of posts, and, the settling of those disputes which at present take up months or years might then be accomplished in as many hours. An establishment of telegraphs might then be made like that of the post; and instead of being an expence, it would produce a revenue."

• Encyclopaedia Britannica, 1797, in the first entry on the telegraph.

Optical Telegraphy in Europe

• Edelcrantz began experimenting with his own optical telegraph designs the month that he read the article about Chappe Within two months he was able to demonstrate a first working version. Edelcrantz's first design still looked much like Chappe's, with articulated arms and flaps.

Edelcrantz would later, after many experiments, switch to a shutter telegraph design that is similar to one of the first designs that Chappe had used in 1791 and 1792 and later abandoned.

• There is no indication that Edelcrantz knew about these earlier experiments of Claude Chappe at this time.Why Chappe rejected the shutter principle and replaced it with semaphore arms, and Edelcrantz rejected the semaphore arms and replaced it with shutters is a mystery.

• Both designs were quite successful, and received much following. For almost half a century, optical telegraphs became part of the landscape in Europe.

The Optical Telegraph in Society

Optical telegraphs can be spotted in the background of many paintings from the period.

Victor Hugo (1802-1885), at age 17, wrote a poem, Le T élégraphe , and it may be the first appearance of a reference to the telegraph in literature

"This cursed telegraph, will it finally cease To importune my eyes which it starts to weary? There, in front of my attic window, it sits quite ridiculous They place a telegraph near my cell! It rises, it drops, and

In these vain movements my inattentive spirit some secrecy seeks..." Le T élégraphe .(1819),

Telegraphs and Church Towers

The telegraph to which the poem refers is that of the Saint-Sulpice church, whose architectural style Hugo despised

Count of Monte Christo:

The Telegraph

In A. Dumas’ The Count of Monte Cristo (1844) we find (Chapter 60: The Telegraph):

“..in the light of the sun its black arms, bending in every direction, always reminded me of the claws of an immense beetle, and I assure you it was never without emotion that I gazed on it, for I could not help thinking how wonderful it was that these various signs should be made to cleave the air with such precision as to convey to the distance of three hundred leagues the ideas and wishes of a man sitting at a table at one end of the line to another man similarly placed at the opposite extremity, and all this effected by a simple act of volition on the part of the sender of the message. I began to think of genii, sylphs, gnomes, in short, of all the ministers of the occult sciences, until I laughed aloud at the freaks of my own imagination

The Evolution to the Wired

Telegraph

The optical system of towers, telescopes, and various signaling devices spread across Europe so that by the mid 1830's there were almost 1000 telegraph towers in a half-dozen countries. But, the optical telegraphs suffered from many drawbacks, not the least of them being rain , mist , and

darkness, all fairly frequent occurrences in much of Europe.

Morse’s Idea

The idea of an electrical telegraph was bandied about by many, but it was often put in the same category as perpetual motion machine.

In 1832, Samuel B. Morse, a painter, was on a ship back from

Europe when he caught the telegraph bug. Seven years earlier, he had been traveling to Washington, D.C. to do Lafayette's portrait and had received a letter that his wife had died. He raced back home, but the letter took so long in transit that he missed her funeral. That experience marked him, and the idea of an electric telegraph hit home.

Morse got off the boat from Europe with the sketches for an electric telegraph in hand and the beginnings of the Morse code already done.

Morse’s Implementation

• Morse in the United States and Cooke and

Wheatstone in England met with many skeptics, but finally in 1844 Morse got his line up and running between Washington and Baltimore and transmitted his first message:

"What Hath God Wrought?"

Surely there is no enchantment against Jacob, neither is there any divination against Israel: according to this time it shall be said of Jacob and of Israel, What hath God wrought! “ Numbers 23: 23 (KJV)

Morse Makes News

• New York Herald, on the occasion of the test between Washington, D.C. and Baltimore:

Professor Morse's telegraph is not only an era in the transmission of intelligence, but it has originated in the mind an entirely new class of ideas, a new species of consciousness.

Never before was any one conscious that he knew with certainty what events were at that moment passing in a distant city —40,

100, or 500 miles off. For example, it is now precisely 11 o'clock.

The telegraph announces as follows: — "11 o'clock—Senator

Walker is now replying to Mr. Butler upon the adoption of the

'two-third' rule." It requires no small intellectual effort to realize that this is a fact that now is, and not one that has been.

Baltimore is 40 miles from Washington. It is a most wonderful achievement in the arts.

The Morse Telegraph Proliferates

The new medium took off like wildfire. By

1850, there were over 12,000 miles of telegraph lines in the United States. The lines quickly circled the world, creating a global network and global industries.

The Telegraph “Business”

• Most telegraphs were sent to a SnailMail® address. The telegraph network would transmit it to the nearest post office (in Europe) or telegraph company office (in the

U.S.) and a messenger would take it to the final destination.

• The problem with postal addresses was that they chewed bandwidth. In Britain, somebody had the idea of coming up with a new addressing system, based on nicknames. Instead of chewing up valuable bits on the line (and paying for those bits by the word), people could refer to a destination by a registered nickname. These nicknames were quite popular, with over 35,000 being registered, yielding a substantial profit for the postal system, the monopoly provider of the namespace.

Telegraph…

Precursor of the Internet

The telegraph spawned much of our modern age. One inventor trying to squeeze more capacity out of telegraph lines was Alexander Graham Bell, who was working on a harmonic telegraph, one that would send several signals simultaneously at different pitches.

When his assistant plucked a reed too hard at one end of the line, Graham heard more than a signal: he heard the unmistakable sounds of the reed itself and realized that the electrical lines could transmit voices . His telephone invention grew even faster than the telegraph; over 30,000 phones were in operation 3 years after the first service began.

Edison

One young telegraph operator, Thomas

Edison, soon turned from fiddling with new hacks on telegraph equipment to electricity, moving on to start the first systematic commercial electrical distribution systems.

Telephone

With the rapid growth of telephone technology, those who had “expertise” in the use of the

Morse code soon discovered that their

“technological skills” were little needed… the prized positions as telegraph operator soon became those of the unemployed… and the face of technology moved on without them.

@ The internet would be the next new wave

Download