Audio Etc. by Edward Tatnall Canby (June 1977)

Home | Audio Magazine | Stereo Review magazine | Good Sound | Troubleshooting


I got so involved last month with Charles Cros of France, the man who conceived of the phonograph some eight months before Thomas A. Edison independently invented it, that never got to some nagging little mechanical questions about Edison's First Phonograph which, in this 100th anniversary year, have been bothering me as never before. Not very epochal questions-just minor tantalizations.

trot them out, even so, because they illustrate a big point about our informational system, that vast transmission belt of second-hand knowledge that makes up maybe 95 percent of our dayto-day reality. Do we trust anything first-hand? It's got so the things we find out for ourselves, right on the spot, aren't as real to us as that omniscient Voice of Authority that comes to us over the air or in print.

In other words, if the weather people say it's fair outside and you see the rain, there must be something wrong.

With the rain, of course.

I have no first-hand experience with the First Phonograph nor have most of us. It's right there, in New Jersey. But you don't just walk in and ask to turn its crank, just to hear the sound that comes out. Like the Declaration of Independence, that machine is now a well -guarded and priceless relic and rightly so. So you read about it. You look at pictures and study diagrams, as who hasn't, this 100th year.

It's all second hand. And the trouble is, when I do this I find holes in the info. Silly little things that in a half second first-hand look I could answer for myself-but no! I have to depend on the transmission belt. Drives me crazy.

So what more do we need to know about Edison? His machine worked. It had a stylus and grooves, it recorded and it played back, no doubt with execrable quality. Isn't that enough? No, not enough, at least until my curiosity is satisfied.

A Question of Curiosity

Question One. Not really a question, since I have figured out the answer-but I'll bet nine -tenths of our readers won't know. Without looking at a picture of the First Phonograph, can you say whether the big cylinder turns along a stationary threaded shaft, to make the spiral groove pattern, or the cylinder and shaft are one and turn together. I had never thought about it, natch. Well, the cylinder and shaft are one. That you can figure out by study of the pictures.

OK, then does the cylinder move sidewise, or does the stylus and its diaphragm assembly (two of these, one for recording and the other for playback)? Well, I can tell you that one too; the cylinder moves sidewise and so does the shaft with it. The shaft is threaded at one end, next to the crank, and screws through the threaded support on that side. On the other side the shaft is unthreaded and moves freely through the smooth bearing hole in the second support.

The styli remain in one place as the cylinder winds past them.

Simple-but note that in later cylinder machines the system was reversed, if I am right. The cylinder turned in one position while the stylus and diaphragm moved sidewise along a sort of threaded track.

Or so I remember.

(My second-hand info, via numerous pictures, is exasperatingly uninformative on this score, as usual, but I think I can make out the traveling stylus, moveable along an overhead screw.) Now this involves some interesting mechanical analogies with present audio equipment tricky motion problems that are directly related to those we face in our overhead -type tangential disc cutters and playback systems. How do you persuade a relatively heavy "carriage", the sonic mechanism plus stylus, to slip sidewise so that the groove is accurately traced in playback without even the tiniest side pull? Those who have designed such systems know all about it-and there are even more recent developments such as the ingenious Teldec TV disc system with its dangling stylus and those "motional feedback" arrangements that give the traveling crane a nudge when it goes too slowly. And on top of all this, there's the RCA laser beam tracking system.

All these mechanisms trace directly back to the very first instant of recorded sound in 1877. The sidewise tracking problem was solved, right there, at least for the moment! Otherwise imagine the sad result: "Mary had a little lamb whose lamb whose lamb whose lamb whose lamb---". Which brings forth a slightly more cogent question. So Edison wrapped tinfoil around a brass cylinder, one in which his stylus embossed or indented a vertical audio signal. Did that cylinder have pre-cut grooves already on it? (Or did the stylus press its own spiral groove onto the foil as the cylinder moved?) Well, I have deduced the answer to that one, too; but look: I have two authoritative pictures of the First Phonograph and they disagree emphatically on this. They are in fact the same photograph, or at least taken at precisely the same angle. But in those days the folks liked to retouch their pictures for greater impact. One of these pictures shows a smooth cylinder. The other shows a cylinder with grooves cut in it.

Wouldn'tcha know. That's secondhand info for you. And Roland Gelatt, in his "Fabulous Phonograph," unintentionally makes for more confusion by writing that "a piece of tinfoil was to be wrapped around the cylinder (with a fine spiral groove impressed on the surface) and two diaphragm-and-needle units..." Impressed on WHICH surface, Roland? The tinfoil or the cylinder itself?

Photographic Fallacy

Actually, I can infer (not having seen with my own eyes) that indeed there are pre-cut groovings on the brass cylinder-retouched out by some idiot in one of those photographs-and thus the wrapped tinfoil lay over these, the stylus gently pressing the foil into the V-shaped space beneath. Tricky, come to think of it, and typical of Edison's fine-tuned thinking, in an area, remember, where no soul on earth had experimented before. It's clear that the precut grooves were not intended for tracking but were a part of the actual embossing system. Would you have thought of it? It was surely a much better idea than forcing the stylus against a flat, non -grooved hard surface beneath the foil.

A baffling unanswered question for me is the tinfoil itself. First--was it tin foil? Made of tin? This was before the days of aluminum, which if it was known at all was then an extremely scarce metal, the electrical reduction process from bauxite not yet having been invented. So-what are the properties of tinfoil, if different from aluminum? If we were to reconstruct an Edison machine today, could we use aluminum foil as an authentic substitute? Probably. Yet in my mind a nagging little doubt remains, maybe not? We would need more info, firsthand.

Now comes the tinfoil clincher.

How, if you please, do you go about "wrapping around" a sheet of tinfoil? Shades of a thousand Xmas packages, all crinkled up and crumpled! How do you wrap a flat sheet of tinfoil so that on a cylinder it will turn nicely and evenly under a stylus with never a wrinkle or fold? To me, mostly a man of many thumbs, this is unimaginable.

I'd have to see it done, first-hand, before my eyes. (As Edison said, only an "expert" could get results out of his first phonograph. Maybe the foil was the problem.) But there is a further problem, about which I have never heard a single word, a matter of sheer topology. How do you convert a flat, finite rectangle into a seamless cylinder or tube? You can't, short of welding and polishing down.

Therefore, in all my second-handedness, I am assuming that the Edison phonograph played with an audible fast tick, tick, tick as the stylus passed repeatedly over the tinfoil joint. What else? Well, maybe it was just a nice, soft purr, tinfoil (aluminum?) being so smooth and impressionable? But that again raises questions about metal characteristics. Hardness, ductility.

My second-hand library on the First Phonograph says precisely nothing.

No help at all. In any case, one would have to overlap the foil the right way, so the stylus would move from the top layer onto the lower-otherwise the point would surely rip the whole thing off the cylinder on the first revolution. Or would it? Perhaps the tinfoil would smooth itself to a near soundless joint, which might have been Edison's canny thought ahead of time. Just like him.

But, of course, that brings back again the matter of the choice of metal. Was tin actually the best, or just a handy choice? How about silver or lead foil? Old Tom was never one to bypass a possible candidate. The differing metallic properties obviously must make some difference. How about gold leaf? Expensive--but the Edison laboratory used all sorts of exotic metals, notably in the electric light filament experiments of the very next year. Platinum, tungsten. So perhaps gold foil might have been used, if it worked well. Or scarce aluminum.

Phono "Printing Press"

Speaking of topology, I have a little whopper of a similar question that has to do with the same sort of change of shape in a different aspect of the phonograph. As we all know, the tinfoil cylinder was soon replaced by cylinders of wax, removable, on which the stylus directly pressed its vertical groove. (No longer any need for the pre-cut grooves, wax being soft.) When Emile Berliner worked out the flat disc and the lateral-modulated groove-at first etched by acid instead of cut or embossed, due to patent restrictions-he also hit upon an enormously important principle, the key to the future audio industry, no less than the mass production stamper system for multiple duplication of recordings, a phono "printing press". Now it is astonishing that for a number of years of heavy competition between the cylinder and the disc, the newer disc records were "published" on a mass scale whereas every single cylinder was individually cut in its wax, aided only by a pantograph system whereby a few cylinders could be cut simultaneously while the performers did their thing. Thus-popular items had to be re-performed live sometimes hundreds of times on end in order to meet the market demand.

Even the use of two or three machines (the maximum, due to close-up recording horns) didn't do much to help. So, oddly, the cylinders of that era, the 1890s, are not in fact identical for a given catalogue item but contain different performances, which adds spice and variety to the reproduced sound. Something we could use today. (Editor's Note: Talk about your direct -to -disc process!) The topological problem was again the shape of a cylinder and its endless circular "plane," like an Einstein time warp. It could not be broken by any sort of joint. And nobody could figure a way to "press" that sort of baffling shape. The problem wasn't solved until 1901, and meanwhile the disc people were stamping out their crude but multiple-pressed duplicates in vast quantities. Curious situation. Reminds us of tape vs. disc today, where tape still can only be copied and copied for publication, if from a single master recording.

Finally, as Roland Gelatt cryptically puts it, "a successful process for molding cylinders was perfected." Period. No further explanation.

Circle of Confusion

Now all I ask is HOW? To this very moment, though I've heard and seen plenty of wax cylinders and still have a few lying around, I am unable to figure out how they were made-how that virgin expanse of grooving was molded free of faults. If you pour liquid material into a circular slot mold with grooves on its outer segment, how do you get the product out? If the mold were to come apart in sections, there would be joint marks and audible breaks in the grooving. If they matched up at all. On the other hand, if the mold comes away all in one piece, it has to expand, grow larger, if it is to break free of the groove surface. (You couldn't have the record itself shrink-that would make it play sharp.) I somehow keep thinking of the (non -disc) brake linings on my car; is the cylinder mold external -expanding? Well, of course I know that cylinders can be molded, and were molded for a quarter century. But nobody's second-hand info has yet given me the slightest idea as to how. That's a typical information hole for you.

P.S. A brilliant idea: how about Babbitt metal foil? Nice and slippery.

(Source: Audio magazine, Jun. 1977, )

= = = =

Prev. | Next

Top of Page    Home

Updated: Sunday, 2016-12-18 1:27 PST