Watches by Machinery

page 5

This is an article we found in the spring issue of Harpers 1869. It tells the story of the new factory at Elgin Illinois. I have placed the pictures in place where they appeared in the text, but I made them a link so you don't have to wait for them to load if you are interested in the text only.


The Compensation Balance-In The Rough, and Finished

The compensation balance comes from the Punching Room a solid piece of steel as large and heavy as a new penny, and inclosed in a rim of brass. It is ground down, worked out, and polished till it becomes a slender wheel the outer rim brass, the inner rim and crossbar steel-lighter and thinner than a finger-ring. Through the double rim twenty-two holes are drilled for the screws. A chuck whirls the wheel around-as one would spin a penny upon the table-four thousand eight hundred times a minute, while a lad makes each hole by applying three tiny drills one after the other. He will bore one hundred wheels per day, or apply a drill oftener than once in six seconds from morning till night-to say nothing of the time consumed in fastening on and taking off the wheels and sharpening his drills. Screws of gold or brass are then put in, and the balance is completed. On this little part alone nearly eighty operations have been performed.

The Train Room

Next we step into the Train Room, the largest and pleasantest in the factory. Seventy-five persons with busy fingers sit at six rows of benches extending its entire length, each before some little machine, shaping, smoothing, pointing, grinding wheels, pinions, or pivots. Cutting teeth in the wheels is done by piling up twenty or more, with an upright shaft passing through the centre of each, and turning a screw to hold them together. The girl in charge then lifts one handle of a little machine, and instantly a steel cutter like a shingle-nail, but with a sharp point at one end, is brought against them, whirling so fast that it looks like a perfect wheel. Whizzing down the outer edge of the pile, it cuts a groove or furrow in each wheel, When it reaches the bottom she moves the other handle; the cutter flies up to the top, and runs whizzing down again. A single wheel has from sixty to eighty teeth, but the girl will finish twelve hundred wheels a day. The long, hooked teeth of the scape-wheel, and the horn shaped tooth of the ratchet, are cut with equal facility.

Cutting Wheel Teeth

In the Escapement and Jeweling departments we first encounter precious stones, in which pivots of brass or steel will run for generations without any perceptible wearing. In the order of hardness they stand, diamond, sapphire, white or milky ruby, red ruby, garnet, aqua marine. In jewk ' they are valued only for their color, in watch-making only for their hardness. Montana begins to supply garnets, but most precious stones come from India, Persia, or Brazil. They are always bought by the carat-theone-hundred-and-twentieth part of an ounce Troy-no matter how large the quantity. They are used not only for jeweling, but also for tools to cut other precious stones or hard metals with. Sapphire is the favorite, because it can be sharpened upon diamond, while a chisel of diamond -the hardest of all known substances -must either be broken to give it a fresh edge, or sharpened slowly and laboriously against another diamond.

The Dutch are the most famous lapidists in the world. They sent workmen from Amsterdam So London to cut the great Koh-i-noor. They will divide a diamond weighing but one carat into two hundred and fifty little slabs, which look like fairy finger-nails. Inserted in brass handles they become ridiculous little chisels, which might turn out wheels and axles for Queen Mab's chariot. Diamond dust also, as white as snow, and finer than flour, has a hundred uses in the factory. An ounce costs five hundred dollars. Metal edges for cutting and surfaces for polishing are "charged" with it; that is, a little of the powder is firmly imbedded in them, and gives them a sharpness which nothing can resist.

Some rare watches are jeweled with diamonds and sapphires, and many with rubies; but for all practical purposes garnets and aqua marines answer as well. The "Lady, Elgin," an exquisite little time-keeper, has fifteen jewels, all of ruby. Four of the fifteen in the " B. W. Raymond" are of ruby, the rest of aqua marine and garnet. The precious stones are cut into planks, and then into joists, by circular saws, and afterward broken into cubes. Then each is turned out in a lathe, exactly as a bed-post is turned in a furniture factory. By this time it weighs less than one- eighty-thousandth of a pound Troy. It is afterwad burnished into its setting-a little circular rim of brass. The hole is made through it with a diamond drill, barely visible to the naked eye, and polished with another wire which passes through it and whirls one way while the jewel whirls the other. The two make twenty eight thousand revolutions a minute. Finally jewel and setting are inserted in a little depression of the watch-plate, which they exactly fill, and held in place by tiny screws of steel, whose deep blue contrasts pleasantly with the bright gilding of the plate.

Every part of a watch must be absolutely accurate, but no part must fit perfectly. To run freely each pivot must have a little play, like a horse in harness; otherwise the least bit of dirt or expansion of metal would stop the delicate machinery. So every jewel-hole is left a little larger than the pivot which is to revolve in it for the "side-shake," and every shaft or axle a little short for the "end shake." The tiny gauges which measure all the parts make allowance for this-a bit of calculation which they perform with an ease and accuracy unknown to poor human brains.

There is another danger to guard against. If the least grain of diamond dust is left in a jewel-hole it will inbed itself firmly in the steel pivot, and then act as a chisel, cutting away the jewel every time the pivot revolves. The new dust of ruby or garnet which this produces will act in the same way" diamond cut diamond"-until the jewel is utterly ruined; so the utmost care is necessary to see that no particle of diamond dust remains in the watch. After the jeweling is done the birds'-nest boxes go to the Finishing Room. In following, let us stop to glance at the Dial Department.

Baking the Dials

The dial, a plain circular plate of Lake Superior copper,'no thicker than a silver three cent piece, is first covered with a paste of fine white enamel, carefully spread on with a knife, to the thickness of three-one-hundredths of an inch. After it dries a little, a workman with a long pair of tongs places the dial flat upon a red hot iron plate In the mouth of a glowing furnace,watching it closely and frequently turning it. The copper would melt but for the protecting enamel, and, at the end of a minute, when he takes it out it is as soft and plastic as molasses candy. The baking has "set" the enamel, but has left it rough, as if the dial face were marked with small-pox. After cooling it is ground smooth upon sandstone and emery, and then baked again.

Now it is ready for the painters. A girl draws six lines across its surface with a leadpencil guided by a ruler, making each point for the hours. Another with a pencil of black enamel traces coarsely the Roman letters from I to X11. A third finishes them at the ends to make them symmetrical. A fourth puts in the minute marks. Then the dial goes to an artist, who, holding it under a magnifier, paints the words "NATIONAL -WATCH co. " in black enamel with a fine camel's-bair brush. The inscription measures three-fourths of an inch from left to right, and less than one-ninetieth of an inch up and down ; but even then it is perfectly legible; and the swift, cunning fingers will paint it twice in five minutes.

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