Chapter I: Introductory remarks
The construction of a good watch is undoubtably one of the most difficult tasks in the whole of practical mechanics. Not only the small size, but the necessity to place the mechanism within a space of a certain shape, the requirement of mechanical perfection and the need for external elegance, are difficulties which are probably not met to the same degree in other branches of mechanics.
Nevertheless, the acumen and skill of the practical watchmaker created many different designs of watchwork and there exist, particularly in Switzerland (the old centre of watch production), an infinite diversity of arrangements which are adapted to their purpose with more or less luck. If we examine these many different expressions of the same basic idea, then the attentive observer will not fail to come to the conclusion that a large number of them were only invented in order to bring out something new and original or possibly to serve fashion. Indeed some create the impression that a watch is an article of fashion and not a scientific instrument.
This was surely one of the main reasons why the Chamber of Commerce in Geneva opened a prize competition for the description of a simple and exemplary watch. Aware of the usefulness of a clear treatment of this matter (and after I had familiarised myself with the production systems in Switzerland, England, France and Germany) I decided to enter the competition, resulting in the satisfaction that my views were favourably assessed by the prize judges.
In 1871, when asked by the publisher of the American Horological Journal in New York, I translated this work (which was originally written in French) into English; and carefully examined and improved it, with some additions which particularly refer to English watches.
It is probably well known that watch production in the United States operates in a completely different way to that elsewhere. The scarcity of skilled manual work led to an expanded use of mechanical aids, which was satisfied to a high degree by the skill and discernment with which automatic and measuring machines were built .
The system of interchangeability, or identity of the parts of a movement, is certainly to be recommended and offers great advantages with large scale production. It was introduced a considerable time ago in some houses in Paris and Geneva, and the possibility of obtaining interchangeability within certain limits can no longer be doubted. But it seems me that this system should not be extended to the production of lever escapements, which should be regarded as individual components in carefully made watches. The cylinder escapement, in contrast, would permit an interchangeable treatment.
Watch production in Switzerland is, compared with the United States, organized in a very different way. In Switzerland ebauches (the frames, wheels and pinions, barrels and clickwork) are manufactured in a number of comparatively small factories. The watch manufacturer buys them and does the casing, dial work, escapement and jewelling, as well as finishing and adjustment.
He would not like to discuss the important principles in the construction of the ebauche, since he seems to be led more by the taste of his customers than by mechanical necessities. This organization causes many irregularities and inconveniences in manufacture; and different major houses, particularly in Geneva, were compelled to undertake the complete production of interchangeable ebauches for their own use in their own buildings, as happens in the watch factories of the United States.
Watch production in England follows the same general pattern so far the ebauche is concerned, but finishing is distributed over the whole country; in nearly every locality watchmakers, in addition to their repair business, construct some or many new watches so that comparatively little pure factory business is found after Swiss style. This system has the decided advantage of offering new work for fashion and important benefits for those who might want to implement a new escapement or something else. On the other hand, ebauche manufacture is at an uncomfortable distance from the influence and desires of most of its customers; and this, with other circumstances of which I will speak later, must be the explanation for some surprising imperfections in the production of high quality movements. Quite probably many English makers realise these disadvantages, but they are not able to force their opinions upon the ebauche manufactures. In the last fifteen years some ebauche manufactures have began to work using systems of interchangeability, but of their success I have learned nothing.
The English, Swiss and French ebauche manufacturers suffer from a common evil, the lack of generally recognized standards and of suitable measuring instruments. In France and Switzerland watchmakers retain outdated systems of units with uncommon tenacity, justified by the "Pied du roi", the foot of the king, although neither country has a king. This system is in total contradiction with the political structure as well as the measurement and weight systems of these countries, and with the normal practices of society. It is completely unsuitable for calculation and comparison, and also it is not appropriate for the size of measurements used in watch work. It should be abolished and be replaced by the metric system. If I am correctly informed, the metric system is already used in those factories in Geneva mentioned above.
The English factories use the English inch, which is as unsuitable for pocket watch work as the Paris line. But most parts are measured by their manufacturers using arbitrary size numbers, without any standard measure and without any guarantee that a certain size number of one manufacturer is equivalent to the same number of another. The disadvantages of this situation could not fail to attract the attention of the thinking watchmaker. Indeed, great inconvenience comes from the circumstance that watch production is spread over the whole United Kingdom, while ebauches and other parts are made only in the district of Lancashire. The manufacturer in London must get ebauches, wheels, pinions, hands and so on from a distance of at least 150 English miles; and it is easy to understand that, in the absence of a generally recognized standard measure, a major exercise is required to do this without committing frequent mistakes.
To change this the British Horological Institute issued a circular in 1861, by which suggestions for a good and practical system of units was requested; and it was expressly noted that it was not necessary that these suggestions should be based on the present English system of units. I submitted a detailed description of the system of units and the measuring instruments used in glasswork, which are based on the metric system. This was not published until two years later, but it was very warmly recommended by the special committee appointed for measurement and measuring instruments. No other reports were published later, except a so-called eccentric measure (which, by its nature, cannot have a definite relationship to a unit of measure), and I concluded that nobody had made any better suggestions. Regardless of the opinion expressed by the committee, there were no followers and English watch work is measured by inches and fractions of an inch to this day.
In my prize paper on the free lever escapement I detailed my opinions on this essay, examined the applicability of the metric standard to all aspects of watch work and also tried to demonstrate its importance.
It is to be deplored that the watch factories of the United States did not introduce the metric standard, which offers such great advantages, from the beginning. There was an opportunity to start afresh because these factories form, to a certain extent, a world by themselves.
Swiss watch manufacturers made their task unnecessarily difficult by creating a large number of sizes. Their regular sizes begin with 10 lines and go up to 21 lines, which results in 12 sizes. Meanwhile, an excessive willingness to satisfy even the most exacting requirements of their customers drove them so far as to implement intermediate sizes of half lines.
English watches have approximately 7 regular sizes. Even this I consider too many, because a gradation of a line (approximately 2.25 mm) is finer than would be necessary even for the most exacting requirements. If 6 sizes were used, which would differ from each other by around 3 mm, then production would be greatly simplified. The sizes would be 31, 34, 37, 40, 43 and 46 mm, which cover the whole range of 13-21 lines. Watches smaller than 13 lines or larger than 21 lines should not be made at all.
The manufacturers of the United States did not make such allowances for the different tastes of the public. It appears to me that they mainly make two sizes of watches, one for gentlemen and one for ladies. The egalitarian character of the republic probably assisted this and, as I am convinced, it has great advantages for the convenience of the watchmaker.
To these introductory remarks I want to add only this: to determine the individual part dimensions I consider it best to express their sizes, if possible, as simple fractions of the outside diameter of the pillar plate.
In my view, the question is:
what arrangement is the best for the cheap production of a simple, but mechanically perfect and durable watch?
This could be answered best by studying the arrangements which have been used, which of them are advantageous and which are most to be recommended; or, where the current methods do not seem acceptable, by striving to produce new designs.