Morse Code is Dead

Samuel Finley Breese Morse died on April 2nd, 1872. The code he devised for the telegraph would last for more than 150 years. Most histories of telegraphy focus on the technological advances. Today let us discuss the code itself. Morse's first version of the Code for use on test equipment dates to at least 1835, and possibly as early as 1832. Not that it lasted unchanged, his first draft only included numbers. Alfred Vail expanded it to include letters and some punctuation. As far as is known Joseph Henry and Leonard Gale who also worked on other parts of the telegraph had no hand in developing Morse Code.  It worked. In 1848, the United States Magazine and Democratic review published an article suggesting that Morse code would reshape the English language to be "terse and condensed". Today they say similar things about Twitter. More here.

Alfred Vail wrote a history of their work that rightly credited some prior advances in telegraphy. However,  in his effort to write Joseph Henry out of history, he reveals a certain bias.  Back in 1832, Morse was a professor of painting and sculpture at the University of the City of New York (now known as NYU.) His knowledge of electricity came largely from lectures given by Professor James Freeman Dana of Columbia College. Joseph Henry, Professor of Mathematics, had suggested the possibility of a telegraph-like device in 1831.  It's hard in that context to credit Morse with the lions share of the technology. But the code was very conceivably his own. One apocryphal story suggests Morse based his system on the quantities of  movable type available at a print shop. To his credit, Vail gives sole credit for the code to Morse.

Since Vail flushed out the code (if it was him) it has changed very little. In December 2003 the International Telecommunications Union added the "commat," a @ symbol to the code. It's rendered as  "· — — · — ·" Prior to that relatively recent change, ITU officials were unsure how long it had been since a change had been introduced. The assumption is that it's the first change since the start of WWII. 

The Modern International Morse code, or continental code, was created by Friedrich Clemens Gerke in 1848. Gerke is said to have changed at least half the letters.  International Morse Code was standardized at the International Telegraphy Congress in 1865 in Paris then endorsed by the ITU.  The original code became known as "American Morse code." In the 1860s, to resolve technical problems on submarine, the dots and dashes were keyed with opposing polarity. Any of those changes, could conceivably have been the next most "recent" update.

The first signs of the end came with the High Speed Telegraph Committee in 1913. The Post master general convened the group to improve efficiency.Overseas duplex and triple duplex configurations were capable of sending more messages on the same cable. Telegraph code books began condensing the messages. Despite that modest improvement the 5-unit Baudot system debuted in 1909 and was better suited to multiplexed lines. (The book History of Telegraphy  by Ken Beauchamp covers this in great detail.) In 1966 ASCII replaced Baudot and Morse began to look a tad archaic. It's use in telegrams had all but ceased as home telephone service was popularized.

Then the endgame: In 1995 the US Coast Guard ceased the use of Morse Code. The The French Navy followed suit in 1997 and Australia 2 years later. In 2003 the World Radiocommunication Conference dropped the Morse code requirement for ham radio licensing. In 1999 the Global Maritime Distress Safety System replaced Morse Code for distress messages. In the US, the last commercial Morse code station KPH/KFS ceremonially sent it's last Morse Code message on July 12th, 1999. They signed off with Samuel Morse's original 1844 message, "What hath God wrought."

Wavelength Formula

In 1917 Audel & Co. published Hawkins Electrical Guide. There the formula for wavelength is described as follows:

"That point where the electric wharp and the magnetic flux meet, or the distance through space traveled during one oscillation cycle is considered the wave length..."

I'd always understood it just as the distance between peaks. The Hawkins definition remained the same through at least 1922 including that archaic use of the word "wharp." Wikipedia defines it very differently today.

"It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a characteristic of both traveling waves and standing waves, as well as other spatial wave patterns."

This formula back in 1917 was given as W = 3.1416 x 2 x 2V √LxC. Given:

• W = Wavelength in meters
• V =  The velocity of light (186,600 miles per second)
• L = Inductance in Henries
• C = Capacity in farads.

You would think a century after the metric system they'd be using different metrics. Clearly this was an American edition. In that form I barely understand the formula. I would re-write that first bit as as "2π x 2V" but who's quibbling?  They're calculating frequency then multiplying by 2π. Today remnants of that formula can be seen in resonance calculations for LC circuits. Such as 1 ÷ 2π x √LC. which calculates the resonant angular frequency. More here.

Today that same wavelength calculation is given much more succinctly as:
 λ = V ÷F. Given:

• V = Wave speed/velocity (in meters per second, m/s)
• F = Frequency in Hertz
• λ =Wavelegnth in meters

It's amazing even today what the metric system has done for our understanding of even the things we already understood.

Twisted Pair and Schweigger's Coils

Let's rewind.

Hans Christian Ørsted determined in 1820 that the electrical charge in a wire deflected an external magnetic field. This is because when you pass an electrical current through the wire it emits it's own magnetic field. This matters because if you coil that wire the field of the adjacent windings overlap with each other. This cancels out electromagnetic noise from sources outside of the wire. Thus was born the twisted pair US patent # 220791. Thank you Alexander Graham Bell. More here. We still use twisted pair cable in Ethernet cable today. It's been over a century and the design remains in use. But Bell didn't invent twisted pair cabling until 1881, That's 60 years later. There was no direct link between Oersted and Bell. It was 1880. They never met and he couldn't just Google it.

Hans Christian Ørsted was Danish, and big on chemistry, physical and post-Kantian. He was also one of the earliest thinkers to describe the "thought experiment."  He also discovered Aluminum.  He was a clever bloke in other words. The oersted (Oe), a unit of magnetic H-field strength, is named after him.  It's a nice way to be remembered. In 1820 during a lecture, Ørsted noticed a compass needle was effected by the toggling on and off of the current form a battery. It proved a connection between electricity and magnetism. That is as far as he got.

Literally a week later André-Marie Ampère began a series of papers describing mathematically how this worked. He also later demonstrated that two parallel wires could be attracted or repulsed by one another, depending on what direction current flowed through them. More here. Shortly thereafter Johann Schweigger deduced that multiple turns of wire amplified the effect the electromagnetic effects of electrified wire on a compass needle. We now call that a Schweigger's coil. Schweigger was a professor of chemistry at the University of Halle in Germany. Ampère  used simple galvanometers like this to measure his experiments.at the time they were called multipliers. Another German, Johann Poggendorf built a multiplier in 1821. University of Cambridge professor James Cumming built a galvanometer with the addition of a magnet to offset the magnetic pull of the Earth. These designs inspired scientists like Prof. Joseph Henry and William Sturgeon to build electromagnets. More here. By 1828 Henry had made magnets that could lift hundreds of pounds. With twisted wires he made simple electric motors. One such diagram describes the wiring

"The galvanic magnet A B is wound with three strands of copper bell wire, each about twenty-five feet long; the similar ends of these are twisted together so as to form two stiff wires q r, which project beyond the extremity B, and dip into the thimbles s t."

Another pre-Bell telephone inventor (there are a few) named Antonio Meucci may have also invented twisted pair. In one of his patent drawings from 1858 he indicated two pairs of two wires each. It is unclear if they were twisted, but it's also not clear why he would have configured a 4-wire circuit for any other reason. It's equally notable that patents by Elisha Gray do not indicate multiple wires on each path. So he is another early contender.

Now you don't actually have to twist the wires together to get some of these noise-rejecting EM effects. Just winding them helped, and even just having them close together did as well. It is highly probably that some engineers running telegraph lines were aware of the noise reduction. But they didn't patent it, or didn't think of it as patentable.  So look at that image at the top of the post. The outer coil is coiled, and the inner wire a set of three twisted wires. That's an image of a marine telegraph line, the original Atlantic cable, run by Mr. Cyrus Field, completed in 1858. It was a Kerite cable. More here. It predates Bell by 20 years but it's still not a twisted pair. Close but no cigar.