The Radio Ranch

1897 was a fascinating year.  (Ignore the book jacket above for a minute.)  Dracula came out in May.  Ever read it?  Not seen the movie — but read the novel?  The original story was nothing like the Hollywood iteration, with bloody-mouthed babes in nightgowns and all that.  The original one is about science.  More accurately, it’s about inferential logic and epidemiology.  Read it, and you’ll see what I mean.  Dracula was published within a year or two of when (a) microbes were first seen under microscopes and (b) their relation to operating room infections was posited.

So 1897 is an age of modelling invisible systems that drive visible ones.

The ether.  Here I come to my point.  In case you wondered, the ether, in 1897, was understood to have a density expressible on the order of 10 to the minus-27th power, calculated somehow ‘from the energy with which the light from the sun strikes the earth.’  It is a substance so fine that atoms sit like marinated cherries within it.  It perfuses all matter in the universe, so that all physical things are in continuity with all other physical things.  Yet things are not continuous with the ether.  Vibrate the ether, and the vibration will pass through distant objects – but the objects themselves will not vibrate.  The earth does not push through the ether, like a boat; the ether allows the earth to pass, as water allows a moving sieve to pass.  Rays, of light or electricity or Röntgen beams, move as vibrations of the ether.  For reasons not yet understood, the ether will conduct every kind of ray through every kind of substance.  Nor does it conduct rays at the same speed through every substance.  The ether in glass carries light at about 120,000 miles per second; through the air, closer to 192,000.  Glass alone, with no ether inside it, allows light to pass at a pokey 3 miles per second.

Oliver Lodge posited that ether functioned in the physics of spiritual life in the afterworld.  That’s another post, probably not on this site.  He was still writing about ‘The Effect of Light on Long Ether Waves’ in 1919 (Nature volume 102, page 464).  ‘The Ether’ was still slang for radio at least into the ’20s.  That too is a whole ‘nother post.  (Now you can look at the illustration above.)

Marconi at Poldhu is only 5 years away now.  It’s amazing, what we can do with the wrong model sometimes.

Says who (except for the Dracula or Oliver Lodge parts):

H.J.W. Dam, “Telegraphing without Wires. A Possibility of Electrical Science,” McClure’s Magazine, March, 1897, pp. 383-92.

The professional community was surprised, and skeptical, when Marconi began achieving reliable communication over long distances. Here is what they deemed knowable at the time they began paying attention.

They wondered what it was that activated the coherer. Magnetism? That doesn’t work, they found. So it was something else. Whatever it is, it even works in vacuums. ‘Making and breaking’ current in an electromagnet, with a ‘vibrator’ or an ‘interrupter’, is how you made a transformer create whatever it was; or you could use alternating current. Artificial daylight apparatus activated coherers, they saw. So did trolley lines. Both of these generated small amounts of spark. So maybe it had to do with spark. But not everyone thought spark was strictly necessary.   W.J. Clark told the New York American Institute of Electrical Engineers in 1898 that he was able to transmit short distances with no gap discharge at all. Marconi, he said, was surprised by this.

As for what these emanating currents did, Heaviside’s model was the gold standard for modelling them.  (Institute president in 1898, Arthur Kennelly (pictured), was so fascinated by this that propagation experts three years later came to speak of a Heaviside-Kennelly layer in the atmosphere.)  The emanating currents go in waves, they could tell for sure. Wave shape seemed to them like donuts. This seemed justified by J.J. Thomson following Maxwell. ‘Hertz waves’ and ‘Lodge waves’ looked like different things, however. Also, waves on the ground didn’t move like waves in the air, they could see as well. They reasoned that the surface of the earth ‘must be a conductor’. They could even tell that waves polarize, depending on whether antennas are vertical or horizontal. Transmitter builders were noticing that finer secondary coil wire worked better, too, though no one could say why.

Transmitting powers matter, they understood. Range goes up as power goes up. They reckoned that something like 95% of a spark coil’s power is used up in heat. They wondered if one could abate this simply with air-cooling, and make a better transmitter. Marconi’s school of thought in 1899 had it that you could also increase the length of your spark to increase your range. Longer spark length ought to mean stronger signals, owing to more EMF. But efficiency was a problem here. Each spark ‘is followed by a series of oscillations’, opined one Dr. Pupin (who also suspected that the number of sparks per second has something to do with the frequency of the signal). He imagined that the sparks dampened each other, depending on how rapidly they came. This attenuates signal strength (and it also generates spurious emissions on unknown and unknowable frequencies). He wished it were possible to generate oscillations without sparks. Hertz too had shown the importance at very high frequencies of finding some way to dampen rapidly decaying waves, for efficiency’s sake. People were talking about ‘decrement’, a special term for the decay rate of oscillations. Overcoming this problem was the rationale behind the ‘quenched gap’ a few years hence.

Marconi’s receiving apparatus was considered insensitive in 1899, a generally troublesome device worthy of abandonment as soon as possible. Coherers limited Morse code speed, to about 20 words per minute. No one had yet made exact measurements of what a coherer could do, partly because better techniques were already in sight. The super-sensitive receiver idea in 1898, the coherer being recognised as a blunt instrument, was a galvanometer. Whatever the receiver, they were inclined to think that signal strength that dissipated over distance requires a longer antenna to receive, because more wire accrues more volts.

Changing wire length brought its own problems. Engineers were aware of frequency changes, in a rudimentary way, and conceived of the possibility of tuning signals. 8-500 ‘breaks’ per second was the norm in 1898 spark transformers, and they could hear the corresponding variations in the musical pitch of the spark. This might be a way of tuning, they thought. Or maybe tuning was going to be a matter of condensers at the antenna feed-point, that control ‘damping’. They weren’t sure. C.O. Mailloux was adamant that transmitted waves resonate (and he used that word) at the receiving end only if the two sets were ‘synchronized’ with each other, so that the waves followed ‘in phase’. What this meant mathematically he wasn’t sure yet. Marconi himself was not even clear what the relationship was supposed to be between the height of sending and receiving wires. But broadly speaking, professionals knew that the electrical properties of transmitting and receiving wires ought to be as congruent as possible. They also knew that antenna size related to wavelength, and logically, that frequency is a function of wavelength. Fessenden declared that wave-length ‘is about four times the length of the wire’ used for transmitting. Thus it is that late Victorians were probably using quarter-wave verticals worked against the ground. (They could also tell that antenna ground connections were better on wet days.)

Says who: ‘The Possibilities of Wireless Telegraphy.’ Transactions of the American Institute of Electrical Engineers. 1899. 607-628. This is the transcript of a New York meeting, held on the same night as a parallel Institute meeting, in Chicago, to discuss Marconi, his assumptions, and his methods.

Photo:  IEEE Global History Network, link here.

Here are the telegraph men waiting on President Lincoln, played (superbly) by Daniel Day Lewis.  I wondered as I watched this how busy the lines really were.

Turns out, all-night press traffic by telegraph was big business by 1860.  Almost every US daily had signed up to the Associated Press news feed, now 10 years old.  The appetite for political news even before the Civil War was so voracious that by special arrangement the New York Herald got the transcript of a speech by Henry Clay hours after he spoke it in Kentucky, clear back in 1847.  It cost $500, which they were happy to pay.*  I notice that Augustus Melmotte, Trollope’s villain financier in the early ‘seventies, stayed in touch with San Francisco and Salt Lake City as though they were suburbs of London.**

Says who:

*George B. Prescott, History, Theory and Practice of the Electric Telegraph, 1860, p. 385 ff.

**The Way We Live Now, Chapter 10, first paragraph.  This is page 47 in the 1875 Harper edition.