This letter was published in the Horological Journal of July 1885 and gives an interesting insight into the Longines factory at the time.
The Longines Exhibit at the International Inventions Exhibition.
I FEAR the undue prominence given in your June number to the American machines may lead your readers to suppose that Switzerland is behindhand with machine productions, and I therefore trust you will allow me space to edeavour to remove such an impression; for certainly one of the most noteworthy and remarkable of the horological exhibits is that of the machine-made watches produced at the "Longines" factory, which shows that Switzerland is not only the birthplace, but also the home, of machine-made watches. It would scarcely be thought, from the neat appearance of these watches, that they were really the results of machine-made work, and I therefore think it will be of service to your readers to give a short account of the Longines factory, and the mode of working.
The factory at Longines were founded in 1866, for the production of watches by machinery on the gauged and interchangeable principle. The factory consists of an oblong building of four and six storeys, and covers a superficial area of several acres, having been twice enlarged. The various machines are driven partly by steam and partly by water. At the commencement, the object the founders set before themselves was not so much the production of a cheap watch, as that of a sound and reliable timekeeper, giving the maximum of results at a minimum of cost and labour. So great is the accuracy now attained by this system, that it is impossible to detect any difference in the pieces even by gauging them. This has been demonstrated to the juries of various exhibitions, by placing twenty-four plates on the top of each other, and holding them rigidly together by means of three rods of straight steel wire passing through the plate screw-holes; the light can then be seen passing through the escapement jewel holes, which in some cases are not larger than 1/10th part of a millimetre in diameter. This remarkable proof of exactitude may now be seen in the Longines exhibit at Messrs. Baume's stand in the Swiss Department, and such a test has never been attempted by any other factory.
Another interesting feature of this system is the marvellous rapidity with which the pieces are produced; e.g. a barrel blank is put into the machine, it is turned inside and outside, the cover without a centre-hole is snapped in, and both holes are cut perfectly true at one operation; then, without being removed from the machine, eighty teeth are cut in the space left on the rim of the barrel, and, finally, a slight hum is heard, caused by a cutter removing the burr from the teeth; the barrel is then complete, the whole process occupying less than two minutes. The cutters move automatically, and the speed of the lathe and the cutters is calculated at the highest rate at which they can be run with safety.
Machinery is also used in the manufacture of the cases; the middle is made out of one piece of metal, without joint or solder; in like manner the bottoms and bezels are rolled out of a flat disc of metal: solder is used only for the joints and pendants; this can be easily seen by examining the rough cases exhibited. In this factory, very great care is exercised in the selection of the raw materials, and none but those of the finest quality are used. At the same time, no labour or expense is spared to keep up the perfection of the stock of machine tools, in order that all the types may be produced with unvarying uniformity.1
Evidently the founders of this establishment place a high value on a good plant, and modern improvements are not with them matters to be trifled with; but, at the same time, it is equally clear that they put a limit to the value of these things. They tell you plainly that these boasted appliances will take you so far and no further; and that for final adjustment, necessary to satisfy the requirements of the present exacting age, they are dependent on a high order of manipulation, combined with great scientific knowledge. As a matter of fact, when the watches are finished, they undergo a last trial. They are once more examined in detail by a staff of superior workmen, quite independent of those in the machine-tool shop. This last control, which is very strict, is a complete guarantee that every watch sent out from the factory has attained the same degree of perfection.
Although the output of the Longines factory now exceeds 1000 watches per week, the complete and important stock of tools will enable the types chosen to be always produced of the same high quality and character.
The system also combines the important advantage of materially assisting the watchmaker in replacing broken or damaged parts, and a special department has been organized to facilitate the repair of these watches, A small descriptive pamphlet has been published, containing numbered diagrams of all the parts of the watch, so that any one in the trade can see the price of each piece at a glance. COSMOPOLITAN.
1 The above remarks may be equally applied to the Longines chronographs.