Part 4

The making and finishing is one of the most troublesome, as well as most expensive of all the processes in watch work. The nature of the material renders it difficult as it approaches so nearly in hardness to the tools used in cutting. In the ordinary Yankee clock, the _lantern pinion_ has entirely superseded the solid leaf, which substitution was the greatest element of success in their cheap construction. The lantern pinion is really a nearer approximation to the required anti-frictional form than a majority of cut pinions in ordinary clocks. In the process of manufacture of the cut variety, the first consideration is the quality of the steel to be used. For this purpose it should be carefully selected by trial, thus ascertaining its fineness, uniformity, softness when annealed, together with its capacity for taking a good temper, with the least amount of springing during the hardening process. Very few pinions are cut from the solid piece--the drawn pinion wire being quite good enough, when milled and finished, for the ordinary run of watch work.

The steel wire having been selected, the first process is to cut it up in lengths a trifle larger than the required pinion. The separated pieces are then centred with care, and having been placed in a lathe, the staff and pivot are turned up to nearly the required gauge, leaving a portion of the whole piece the full size for the leaves. They are now taken to the milling tool to have the proper form given to the leaves. As this form is of the highest importance, it may be as well to give here the reasons. Supposing a wheel of 60 teeth, depthing into a pinion of 8 leaves, it can readily be seen that the arc of the motion of the wheel tooth is of greater radius than that of the leaf of the pinion, and it follows that if the teeth and the leaves are made in taper form with straight sections, there must occur a sliding motion on the surfaces of both--the power thus absorbed being totally wasted; but if we curve the surfaces we may approach a form so nearly perfect that the wheel teeth, being motors, really roll on the leaves, avoiding almost entirely the friction caused by sliding; the necessity for this curvature becoming greater the more the wheel exceeds the pinion in diameter. This curve, which has been demonstrated by very profound mathematical researches, is the “epicycloidal;” theoretically it should give no more sliding motion than the surfaces of two plain wheels revolving on each other. To obtain this perfect form, very great pains have been taken and expenses incurred, especially by the makers of the best time-keepers.

In the American factories the cutters are very elaborately made, the section being an object of great solicitude--it being an exact counterpart of the space between any two leaves, and also of one-half the top of the leaf from the curvature to the point, so that in milling, the space made by the cutter is its shape, leaving the leaf of the proper form. Generally the pinion passes under two cutters; the first to strike down the rough stock, the other to dress it to size and shape, with a light cut. The care and skill required to make these is certainly very great, and it is a proof of the wonderful ingenuity of man that they are made so perfect as to shape and cutting power.

A very ingenious device is used for dividing the leaves under the cutter, which revolves at a moderate speed over a slide, carrying a pair of centres, between which the turned up piece of pinion wire is placed. The slide is now pushed up to and under the cutter, and in its passage as much of a cut is taken as is desirable; in drawing back the slide the fresh cut space passes under a flat piece of thin steel, screwed on the frame, and set at a slight angle to the axis of the centres. On moving the slide towards the cutter for a fresh cut, the steel plate takes the last cut, and in passing by it the pinion is turned just as much as the angularity of the plate, which must be just one leaf. By this very clever device the division is effected without an index plate. This process, however, is not good enough for work intended to be very accurate--the pinion wire not being always, or indeed rarely correctly divided, the original error will be perpetuated in all the subsequent processes. These are all milled, with oil or soda water for a lubricator, and it follows that the speed of the cutter is regulated to get the greatest cut without dulling the tool. When dull, however, the mill is sharpened on the _face_ of the cutting tooth by means of small grinders of iron, using Arkansas oil-stone dust for the first grinding, and giving the necessary delicacy of the edge by means of crocus, or sharp, followed, when fine work is needed, by rouge.

It is necessary that this care should be taken, for if the edge is left coarse it will become speedily dulled, and leave a very unequal and rough surface on the cut of the pinion, which in the subsequent grinding gives rise to error in shape and size. The pinions, thus cut to gauge, are dried in sawdust, hardened, and tempered; the staff and pivots are now turned up to size, and then pass to the polishers. In the factory they are finished by means of what are called _Wig-Wags_, which it may be interesting to the reader to have a general description of.

Two Vs are arranged as centres, the pinion is placed between them, the circular parts resting in each V, but free to turn on its own axis. Immediately above the Vs is a frame on which a slide, carrying the polisher, may traverse--generally about two inches. This slide is movable vertically so as to accommodate itself to the pinion; attached to the slide is a connection which leads to a vertical lever, which is put in motion from a crank on the counter shaft. The grinding is effected by bringing the grinder, charged with oil-stone dust in oil, in one of the spaces of the pinion, which, of course, is so arranged as to bring it parallel and central with the grinder. The power being applied, the slide takes a very rapid reciprocatory motion, and the face of the grinder, so charged, rapidly reduces the uneven surface left by the cutter to what is called the _gray_.

The form of this grinder must be as perfect as the cutters, and the care taken to get the requisite parallelism is in equal proportion, and in all the best polishers is planed up while in its position. The grinder is composed of tin and lead, with sometimes a slight admixture of antimony, rolled to an even thickness, cut off in suitable lengths, and then mounted in the carrier of the Wig-Wag to be planed up to shape. There are too many minute adjustments in the machine to render a full description in this article admissible. It is large compared with the work it has to perform, but it is very admirably made, as indeed all the tools are, in the American factories.

The polishing of the leaves is the next step, and this is effected by means precisely the same as grinding. In each stage the pinions are thoroughly cleansed before entering on another. The polisher is made precisely like the grinder; but instead of oil-stone dust, crocus mixed with oil is substituted. Owing to the less cutting quality of the material used, the polisher loses its form sooner than the grinder, and has to be more frequently reshaped. In very fine work the crocus is succeeded by fine well-levigated rouge to bring up that jet black polish, which is considered a mark of quality by chronometer and watch makers.

With the exception of turning up the staff and pivots, all the work hitherto described has been expended on the leaves--a very tedious process, yet done, when the tools and materials are in proper order, with marvellous rapidity; but tedious as these have been, there are two others quite as much so before the leaves are finished.

The ends are to be faced--they must be flat (that is a true plane) and receive the same finish that the leaves took, and is effected by the wig-wag; only the pinion revolves between centres, at a high speed, the grinder being brought up to the turned face. Two motions operate--one rectilinear, the other circular--the result being a compound motion which prevents the grinder from touching the same spot twice in succession. To effect this more surely, the operator gives the grinder a slight vibratory vertical motion. The polishing of the two faces is effected in the same manner as the grinding; in all cases the cutting face of the grinders and polishers being kept in a plane perpendicular to the axis of the pinion, both vertical and horizontal.

The staff and pivots being in the same condition they came from the lathe, the next step is to grind and polish them. Before, however, we treat on this process, it may not be amiss to give the general watch repairer a process by which the facing may be done on a small scale.

As a rule, when the watch repairer has to replace a pinion he selects one from the material dealer, finished in the leaves, but not on the ends or faces. The following operations are simple, and any one may finish these faces with little trouble. Having turned up your pivots and squared down the face of the leaves with the turning tool, grind it in the lathe by means of a ring of metal, the inside diameter being somewhat larger than the diameter of the staff. This ring is held between two centres, thus allowing it a vibratory motion, so that when it comes up to the face it accommodates itself to its plane, and thus has no tendency to force it out of a true flat; the ring, being larger than the staff or pivot, admits a small lateral motion, enough to effect a continuous change of surface. The same little tool may be used for polishing by substituting another polisher and using crocus and rouge. For the repairer, perhaps on general work the rouge would be superfluous. Vienna lime, used with a little slip of boxwood, brings up a very fine and brilliant polish, and in replacing new work in an injured time-piece, the steel may always be polished with great rapidity by using the lime on the gray surface left from the oil-stone dust; being quickly done and affording a very handsome finish.

To resume the consideration of the pinion, the last stage is the polishing of the circular portions. Here again the wig-wag is the most useful tool, but it operates somewhat differently, for the grinder or polisher is pressed down by the finger of the operator, the pinion being held between the centres of a small lathe attached to the wig-wag; the staff is first ground and polished as the leaves have been before, and this is the last operation performed with the pinion between centres. From this stage it is chucked in a lathe very peculiarly fitted, the mandrel being hollow; and in it is fitted what is called a pump-centre, which is movable in direction of the axis of the mandrel, and capable of being securely fastened at any desired point. On the nose of the mandrel is secured a hollow steel chuck, the two sides of which have been filed out, thus leaving an open space between the end of the pump-centre and the end of the chuck. On this end a small steel plate, extremely thin, is fastened by means of shellac, and a hole drilled in the plate capable of taking in the chamfer on the shoulder of the pivot. The pump-centre being drawn back, the pinion is introduced into the chuck, the pivot placed in the hole in the steel plate, and the pump centre is drawn forward until it forces the chamfer to fill the hole; the pivot projecting from the chuck is now ready for all the grinding and polishing processes. Here the wig-wag steps in again, and from the delicacy of the pivots is modified to suit the case; this is done by having a polisher hung in the wig-wag on centres, so it may revolve; when in operation one side of the polisher rests on the pivot, the other on a ruby placed in a screw, and which screw enables the operative to insure the parallelism of the pivot. The ends of the pivots are next rounded off and finished in another set of tools. The pinion is now ready for use, assuming it to be of the proper gauge. In the American watches the scape and fourth wheels are generally staked on the staff pinch tight; the third and centre are staked on the pinion leaves, a rebate having been turned down on the ends, the wheel set on the shoulder, and the projecting ends of the leaves riveted down. This has not been designed as an exhaustive article on pinions; it is merely intended to open the subject as pursued in the factories. There is much more to be said; and the various processes on the small scale, as performed by the Swiss and English, together with their tools, will bear more than a general description, as they are applicable at any watch bench.

The subject will be continued, in the effort to give a full and useful article.

New Three-Pin Escapement.

A contributor to the _London Horological Journal_ gives the following description of his invention:

“The merit of this escapement is in a newly invented escape-wheel which is self-locking and requires no banking pins; the pallets are curved inside the impulse and outside the locking, to work with the curved points of the teeth of the wheel; being made of gold the wheel will go without oil. From its form it has the power of double impulse and double locking with the lever. The first takes place at the discharge of the escapement, the second does not act unless the watch receives a sudden motion, and then the pin or pallet in the roller strikes lightly on the lever, when the propellant power drives it back again. The balance passes through two turns before the second locking takes place, and is formed so as to be able to take up the lever, and the watch soon rights itself, and its time will not be affected. Another advantage is, that the lever is made of a flat piece of steel, as I have introduced a gold stud to receive the ruby impulse stone, which is made to adjust easily so as to bring the escapement to the closest geometrical accuracy. By its formation this ruby guides the impulse to the external edge of the roller notch. These advantages, and its simplicity, render it suitable to the best chronometer watches.”

A FEW years ago, in 1859 or ’60, Mr. Peabody, a very talented gentleman of this city, patented a three-pin escapement that performed extremely well. A full description of his patent and plan is not at hand, but we will endeavor to give it to our readers in our next issue.

English Opinion of American Watch Manufacture.

In the London circle of Horologists, more attention is paid to the scientific departments than the mercantile; but for all that, a Mr. Henry Ganney has held forth before the “British Horological Institute,” on “American Watch Manufacture.” Though an Englishman, with English prejudices, he certainly gives a very fair and impartial statement of the subject; yet he views it almost entirely in the money-making aspect. He gives all the credit deserved to American enterprise and ingenuity, and yet there is a certain sense of a drawback. He had before him samples of machine work; among others, to quote, “several movements made by the British Watch Company, which flourished and failed about twenty-five years ago; these were machine-made, and the perfection and completeness of the machinery they used for producing these frames has not been equalled, I believe, in America; several machines being used there to accomplish what was begun and completed by one here.”

Mr. Ganney is right in his statement, but the example given by the British Watch Company was the rock seen by the American navigators. One tool, for facing off, truing up, drilling, depthing, and doing all the work on the pillar plate, having cost, before completion, some three thousand pounds sterling, and from its very complexity being utterly inefficient--worse than useless. In the very inception of the American watch manufacture a similar mistake was almost made. Experience and sound reasoning proved, however, that a multiplicity of operations in any one machine rendered it entirely too complex, the adjustments too numerous, and the work totally worthless. We shall in another number refer again to Mr. Ganney’s lecture, and perhaps give some beamings of light on the early history of the American watch manufacture, derived from personal observation at the time.

Correspondence.

EDITORS HOROLOGICAL JOURNAL:

I received a Prospectus a few days ago advising me of your contemplated existence. I could hardly believe the fact; “the news was too good to be true.” However, I shall take it for granted, for I cannot see why somebody has not before had the enterprise to launch out in the periodical line on subjects connected with Horology, the field being so extensive and the want so severely felt. Enclosed I send you the subscription price; in this much I have accepted your invitation, but I also enclose some few lines on a subject not particularly practical or theoretical, but very near the truth, and may perhaps give you a view of our wants.

To tell the “plain unvarnished truth,” I am a watch repairer, located in a small country village, with a decent stock of tools and a moderate trade. In all this I am no exception; so I write this in the name of all who are similarly situated. Isolated as we are, we (the country village watch repairers) have few means to improve our knowledge of the trade, but work on the same old principles learned when we were boys and apprentices, and of better and more expeditious ways of doing our work we are entirely oblivious. True, our friends of the Hebraic persuasion, who, angel like, bring us face to face with the outer horological world by selling us material and tools, occasionally present to our benumbed vision something new, such as a Swiss lathe, or lathes used in the factories; but of what use are they to us? We purchase one; well, on the bench it may be an ornament, but for use, drilling large holes is the height of our ambition. We have not the time to learn by self-experience all the boasted usefulness and capacities of the tool; so we go back to our old verge or Jacot lathe when we have to put in a pivot or a new staff. We may know all about the escapement and be able to detect the cause of any trouble with it, but we have no knowledge of the latest modes of repairing the injury when it is discovered, and this knowledge is what I hope to find in your journal. I live in a section where the general class of work is of a very low grade, even the old verge being very common. Our stock of material has to be heavy in proportion to our trade, and then once in a while we are compelled to send our work to the city, some sixty miles distant, in consequence of not being able to do it, either from a lack of the material or want of a proper tool. To all intents and purposes we remain as stationary as the oyster. Not only do we have these vexations, but the ignorance of the public at large as to the treatment of their time-keepers is a fruitful source of annoyance; we are often charged with fraudulent practices, and a certain degree of caution is observed by more than the most ignorant. Thus, a few days ago, a stalwart son of the Green Isle made his appearance in front of the counter, and, projecting in front of our optics a huge English double-cased verge watch, spoke in almost dramatic tones:

“Plase, sir, av’ ye could make me ticker here go, sir?”

Answering in the affirmative we reached for the silent “ticker.” He drew back with alarm.

“Bedad, an’ ye’ll not stale a morsle frae this?”

“Well, but let me see the watch.”

“An’ will ye let me eyes be on yes all the time?”

“Yes.”

“An’ yes’ll not stale a jewil?”

“No.”

“Thin, there it is.”

On looking at the movement the verge was found broken, the injury explained, and the price given. He decided on the repairs being done, but said, “Give me the watch now and when ye gets the thing fixed its meself will come and git it and pay yes.”

“But we cannot repair the watch without having it.”

“Faith, thin, ye’ll not have it; ye’ll be taking something frae it.”

Now, this is an extreme case of ignorance, pardonable, perhaps, in this instance, but the public embraces multitudes just as ignorant where an allowance cannot be made. I do not expect the JOURNAL to reach such cases, or to influence the general mass, but my hope is that it will, by raising the general self-respect and tone of the repairers, indirectly elevate the respect felt for them by the public at large.

But I am writing too long and rambling a letter. I wish to express my hearty wishes for your prosperity. And, in conclusion, will you allow me to express a hope that you will give us the knowledge we need--that is, post us up on the minutiæ of repairing in the latest styles, the newest processes devised, and, above all, give us an article on the lathe and its uses?

Yours truly, W. L. C.

We have the pleasure to give our correspondent the assurance that an expert will contribute to our next number an article interesting as well as valuable in instruction as to the use of the lathe.

Eclipse of the Sun.

The approaching total eclipse of the sun, on the 7th of August next, is exciting much interest. The obscuration first occurs in latitude 39° 53´ 3´´ north, longitude 138° 37´ 4´´ west--Washington being the meridian. The first totality is on the Pacific coast of Siberia, at sunrise, in lat. 52° 41´ 9´´ north, and long. 165° 26´ 4´´ west. The eclipse is total at noon in Alaska, lat. 61° 46´ 9´´ north, and long. 68° 4´ 6´´ west. The line of the total eclipse now runs south-easterly, grazing the coast near Sitka, thence north into British America; then entering the United States, near the head of Milk River, long. 30° W.; thence through the south-west corner of Minnesota, diagonally through Iowa, crosses the Mississippi at Burlington; thence through Illinois, a little north of Springfield, crosses the Ohio river at or near Louisville, Ky., passes through the south-west corner of West Virginia, through North Carolina, just south of Raleigh, ending on the Atlantic coast at sunset, just north of Beaufort, N. C., in lat. 31° 15´ 2´´ north, and long. 9° 36´ 6´´ east. The line thus described will be that of totality, only partial in any other part of the United States.

The United States Government is, or has been, establishing a meridian line at Springfield, partly to make observations on this coming eclipse, and with the further view of determining a standard of surveyed lines--all of the Government surveys in Illinois having been geodetic. Professor Austin, of the Smithsonian Institute, is in charge of the work, aided by an able corps of assistants.

Diamond-Cutting.

At the Great Exhibition in Paris, in a part of the park contiguous to the Netherland section, M. Coster, of Amsterdam, has erected a building wherein all the processes of diamond-cutting are carried on.