These stones form the general stock by and from which jewels are made. The details of the various manufacturing manipulations, the tools used, also the setting in the work, together with the important item of the screws, will form the subject of the next article on Watch and Chronometer Jewelling. Not having been able to get our engraving done in time for publication, we are compelled to reserve the remainder for the next number.
Hints on Clocks and Clock-Making.
NUMBER ONE.
Twenty-five years of hard labor amidst the dust and din of machinery, with hands cramped, and fingers stiffened by the continual use of tools, and with a brain constantly occupied in ringing the changes upon wheels and levers in their almost infinite combinations,—it requires a degree of courage to undertake to write anything that can be dignified with the name of an “article,” although it does propose to treat upon a subject with which we are fairly familiar; but it is consoling to think that one is not expected to write for the pages of this practical journal with the same degree of elegance and polish that should grace the columns of a review or magazine; that we can appear here as plain, practical mechanics, and use good hard, round words to express our ideas, backed by an experience which should add some weight—and we welcome the appearance of the “American Horological Journal,” which is to serve a good purpose by bringing out the actual experience of men who have grown gray in the art and mystery of clock-making, and preserving, by means of the “art preservative of all arts,” their dearly bought knowledge and experience, for the benefit of those who in their turn shall follow them; and it will also benefit the people in general by giving information that will lead to the purchase of good and tasteful clocks for household use.
That such a journal is needed to enlighten us, is made plain by the fact that in almost every newspaper we have a vivid account of some wonderful clock “recently invented,” which may possess some merit, but they are so grossly exaggerated by some ignorant “penny-a-liner,” that we are almost led to believe in the Irishman’s marvellous “eight-day clock, that actually ran three weeks.” Even the proverbially correct “Scientific American,” of which I am a constant reader, has in its issue of June 19th, an account in its “editorial summary” of a clock in France containing “90,000 wheels,” and perhaps the most curious part of the mechanism is that which gives “the additional day in leap-year,” etc. Now, it will require but little knowledge of clocks to tell us that one with 90,000 wheels was never made and never will be, but “the additional day in leap-year” has been given by calendar clocks in this country since the year 1853.
It is not proposed in the series of articles to follow, to discuss the early history of clocks. Reid and Dennison have written enough to convince the most skeptical that the clock is an old invention. It is not important to us who invented the pendulum, or this or that escapement, but who makes the best pendulum, the best escapement, the most perfect train of wheels and pinions. These are vital points, and we shall endeavor to give them that attention that their importance demands. It is proper to state here that any assertion made, or rule given, has been tested, and is the result merely of our experience, and we do not claim that it is all there is of the subject; for we are aware that the experience of others may have led to results entirely different; but if all clock-makers will avail themselves of the columns of this journal, we shall not only become better acquainted by an exchange of ideas, but better clock-makers.
The subject of wheels and pinions is of the greatest importance in clock-making, and the utmost care and skill are required to execute a train which shall not only run with as little friction as possible, but the friction must be equal; for if there is no variation in the train force, the escapement and pendulum will always be actuated by the same amount of power, and the performance of the clock can be relied upon. Clock text-books do not fully impress this subject. We find a great deal upon this or that escapement, and the different pendulums. Dennison has a couple of pages full of abstruse calculations upon a method of shifting an extra weight upon a rod, so that the going of a clock can be varied one second per day; but if his wheels and pinions are not perfect, a large tooth here and there will vary the clock more than that.
Reid overawes us with his knowledge of the proper curves of the teeth of wheels; but it must have been only theory, for his practice was to saw his teeth, and his cycloids, epicycloids, and hypocycloids were left to the mercy of the “topping file” in the hands of his “wheel teeth finishers,” instead of shaping up the teeth in the engine, as is done now. We have generally cut the wheels of fine clocks over several times with different cutters before taking them from the engine; the last cutter having but one tooth, which can be made perfect as to cut and shape, and, running with great speed, will leave the teeth the proper shape, very smooth, and as true as the dial of the engine. Escape wheels, especially, require great care in cutting, as the teeth for dead-beat escapements are somewhat long and thin; the least inaccuracy is certain to cause trouble. It is absolutely necessary that the dial plate of the cutting engine should be perfectly true, with clean, round holes, and a perfect fitting index point, with a cutter arbor without end play or lateral motion—these are the essentials of a good cutting engine, without which a good clock cannot be made.