MAKING RECORDS.

Star (Christchurch), Issue 10236, 19 August 1911, Page 1

MAKING RECORDS.

Ecw the Phonograph is Supplied. * ■ Intricate and Solic&ta "Work. One of the most interesting processes at the great Edison works in Orange, N.J., is that by which the latest type of phonograph record is made. When Edison invented . the phonograph it was naturally the etrange "talking machine" that impressed popular imagination, and to this day the machine itself is regarded as the real wonder. Before Edison had gone far in perfecting his invention, however, he saw that the really marvellous tiling was tho record. A phonograph is only a mechanism for manufacturing eoundvibrations. Its parts are simple. It has been refined, but making It is only a matter of assembling parts, like any other mechanism.

But phonograph, records are not simple. Edison says their possibiltios run off into infinity. First he used paraftincd paper, then tinfoil, than waxes, then insoluble soaps, of which master records are still made, and the blanks familiar in. office dictation. Yet the ideal composition was not found. A hunt began over the whole world for waxes, gums and resins to be tried in combinations, including the fossil subeances. These yield satisfactory compositions within certain limits—the chief ingredient of records to-day is montan wax, extracted from brown coal, a fossil which is the amber of antediluvian palm trees. Evidently Nature's products in this lino were exhausted. Now his chemists have pushed far into the aromatic aeries or hydrocarbons,, searching for the ideal synthetic ''conrpo.'' Not long ago Italian chemistry made synthetic attar of ruses of these hydrocarbons, and that promises well for the ideal phonograph record.

The entertainment record, bearing a soprano solo or vaudeville monologue, is made by moulding. First you catch your prima donna or vaudeville- artist, make your master record on the aoi't blank of insoluble soap, and when it is approved put it into a battery, where a shell of pure gold is deposited oji all tho microscopic indentations by electro-plating. The outside of this shell is then electroplated with a strong shell of copper, for rigidity, while the inside is plated with a thin film of nickel, because the composition sticks to gold. Gold is the base because it most faithfully reproduces all the indentations of the master record. There are about 500 of these to tho inch of "scratch" or several millions on the longest records. Assume that the record was made by an orchestra of thirty players, and reproduces intricately mixed tones ranging from piccolo to tuba. There you have something complex, but it is all on tho phonograph cylinder. Edison's experience with the phonograph has given him a profound sense of wonder, not for the mechanism that can record and reproduce complexity, but for the human ear, which can distinguish tho harmony in it. Well, take your electroplate shell, put it in a steel jacket and you have something like a _ tall, thin French mushroom can. This is the mould from v. hich reproductions of tho master record are cast lor sale. Until recently the casting was done by hand, a boy lowering the moulds into melted composition, letting the in fill by gravity, and setting the;a aside to cool. This "cpmpo," harder than that of tho master record, and of wholly different character, made durable records with a hundred threads to the inch, giving two

minutes of entertainment. Edison wanted a four-minute record of the same size. He got it, finally, by a new composition that is harder, and takes twice as many threads. This new " compo" must be handled by a wholly different routine. Instead of cast, tlie rcords are spun. Instead of handwork by one boy ; there Is a machine run by a crew of eight men, who play together like a baseball team, and tho quality of their team play affects the product. The process begins by heating the moulds to 270 degrees Fahrenheit, which is tho heat of the melted composition. If the mould were a trifle cooler it would chill the hot " compo," trap minute air globules and create difficulties that we will look into presently. The hot mould is passed into a machine, where it begins a three-minute journey along revolving drums that whirl it at high speed. Just bei'oro it is fairly off, tins machine fills the space between the mould and its core. Centrifugal motion then forces liquid composition into every tiniest crevice of the mould. These indentations aro measured by one-thou-sandths of an inch. The surface of a four-minute record looks like tine watered silk. When the spinning has filled the mould, it goes, still hot and whirling, under jets of cold water. These temper the record surface as steel is tempered. It is done so rapidly that the inside of the record is still molten. The rest of tho passage through this machine is given to cooling the inner surface and taking the mould out at tho proper temperature. Eight men work this maoliine. If one is a new hand, production will be about the same, but the proportion of defective work goes up from 10 per cent, which is normal, to 30 or 40, and there it stays until the new man learns to play ball with the crew. The first winter these records were subjected to freezing weather, complaints began to come in from agents m the north-west, accompanied by records showing small sections broken from the surface. At the bottom of each hole was a minute cavity. It took two months to find and remedy that trouble, which was due to tiny globules of water being whirled into the molten composition through some leakage, and kept there until the composition cooled, when it was imprisoned. Months later zero woather in Minnesota turned that globule to ice and expansion burst off a fragment of the reoord surface. Tho result was frozen phonograph music. Somebody reminded the superintendent that architecture is frozen musio, but he eaid he didn't see it. Since this trouble was remedied, a hundred re T cords are picked out systematically every day, winter and summer, and frozen as a test. No difficulty is ever encountered in hot climates,' for the composition stays solid up to 180 degreos, its melting point. But here is our warm record, leaving the spinning machine in its mushroom can. How are we going to get it out? Remember, tho inside of that can is lined with several million delicate indentations, representing music or speech. We filled it with liquid comand used centrifugal motion to force it into every crevice. Tho composition, being hot, still presses outward into tho threads on the walls of our can.

One way to get it out is to wait ti]l the composition slightly shrinks bycoolh\z. But that will take a day or more, tving up our moulds for thirty hours. This is a costly item where 150,000 records are made daily, for it means heavy investment in moulds. Another way is to cool the mould artificially. That was the method followed until'a question of patent rights made it necessary to find another, and, as usual when men are driven to find, a new process, they found a better—vacuum. Air is now exhausted fn the centre of the mould iust enough to shrink the warm record about one two-thousandth of an inch, nnd it is lifted out, and the mould put into use ag<n'n immediately.

j Edison himself couldn't lift that warm record out int*«t, nor the superintendent either. Those indentations fn the walls of the mould aro sharp, and the record has been shrunk so very plin-htfy that, if lifted inaccurately | either vray by a thousandth of an inch, it will he scratched and ruined. The men who do this work must neon ire a deftness tha.t is true sleight-of-hand, ■ and the green hand there spoils nine* ! re-cords in every ten until he acorn'res the tnVk. Then he takes out ZQOO a day, with small percentages of defects. The average "mannfnrhvrinrr plant works by percentages of output. ~Thi° plant, however, goes by peropntnsres of defects, and wages are pe.id by -more system, based on perfect work." From spinning machine to final packing: for sale, records are handled eleven tfrnns. each operator rejecting: and spoilinc pome of the previous operator's perfect. fW Tvhieh the Tetter has beer, paid. The msn who takes records out of +,ho moulds snoils some, and a prir) at, his side scratches seme more, placinethem on pes in trays. Then the fi r si inspector examines their surfaces nndo> st'-rtTiT light for minute scratches and pinholes. A pinhole, one-half of one-thousandth of Rti inch deep is not visible to a stran<rer. T« tho series of records that make ut> n Chinese sonf —-one Chine,'!?! sou<r carried in stoek is distributed over twelve records, end takes half an hourto rdav—«n-c.h a Heck mi'srht not mastho effect. But on the phonorrra.ph. it will mak* a noise, to Occidental par?-,, like tho flamming; of a f!nf!f. T't's inppcotor rejects marnr cords, and spo'l» a few. They £o to a ■sorter, who spoils some. A hoy bezels tho cdrPT. find spoils snme, .Another Hiv whitens the embossed letters of -ii+le at one end. end spoils some. A causer test"? inner diameter, rejects «nm« and spoils some. Finally, another inspector and three packers spoil ("'■>""■- pprronta,>?res. a preen operator anywhere. in this ehain and suddenly the percent-nn-o of defects "Rejected records "o hack to the melting: pot. Tf a sufficient number so back too oft<m. certain in<rr n d''ents of iha compMft'on are ln=t in rehentiurr. Scrme morn it? t.bo percentage of defects himns to 70, and work must be stepped until tho eomoosition is adjusted. "When the plant is working en 10 per cent of defects, that is considered normal.