By Bruce Shawkey
Eterna was founded 1856 by Josef Girard and Urs Schild. in 1882. Six years later, Urs Schild died at age 58. His son Max took over the company and soon made a business trip to the United States. He returned to introduce machinery to the craftsmen. Max Schild was ahead of his time and his ideas were unpopular. Discouraged, he left the company and handed power over to his brother, Theodore, who turned Eterna into a prosperous 20th century business.
In the early 1900s, wristwatches were just starting to become fashionable. In 1905, Schild Fréres, as the company was then known, changed its name to Eterna. The company continued to be at the leading edge of wristwatch development, and in 1908 it patented the first alarm wristwatch. The watch went into production in 1914.
By 1932, Eterna had set up a subsidiary company, ETA SA, to make movements for itself and other Swiss watch companies. This same year, Theodore retired and handed over the control of the company to his nephew Rudolf Schild. Here is one of Eterna's watch from a 1942 advertisement:
In 1948, Eterna advanced self-winding watch technology with the development of the Eterna-Matic automatic movement. The use of five strategically placed ball bearings made the movement very efficient and significantly reduced friction and resistance on the oscillating weight. The five ball bearings became the logo for Eterna-Matic.
Between 1948 and the present, Eterna and Eterna-Matic was bought and sold several times. It is currently owned by Swatch Group. Eterna-Matics are now featured as one of many Swatch Group's brands.
Here is a history of Eterna-Matic published in a 1951 edition of Europa Star magazine:
Eterna-Matic
The first automatic watches
The conception of a watch which would wind itself of its own accord while being worn goes back over 100 years, but wristwatches have been used for only a few decades. The earliest automatic watches were pocket watches in which a lever was installed to swing freely at a certain angle in the plane of the movement and above the middle: that is, between the movement center and pendant. The motions of the lever were transmitted by means of the action of a gear shaft on the barrel-arbor which was turned slighthy by each motion of the lever instead of by the winding stem. To avoid over-winding the mainspring the outer end of the spring was not attached rigidly but fastened to the barrel-arbor by means of a flexible bridle.
The energy for winding the mainspring was provided by the natural movements of the wearer, as, for example, when walking. Through these natural movements the impulse lever started oscillating. The effectiveness of this winding arrangement depended primarily on the inertia of the weight of the impulse lever in addition to its length, which was limited in the watch. This lever was also thickened and widened as much as possible at its lower end. The principle of the oscillating lever has always proved the most serviceable for automatic winding mechanisms. The present-day oscillation weight developed from this oscillating lever, while at the same time the anchor-shaped lever was extended to approximately a semi-circle, yielding the greatest possible turning momentum of a given cross-section.
Ladies' automatic watches
In the application of the automatic principle to ladies' watches, a great primary problem known to every engineer is immediately apparent: that the degree of efficiency of a machine diminishes as its overall dimensions decrease. The reason lies in the impossibility of minimizing the unavoidable losses caused by the motion of the energy-consuming parts etc. in proportion to the gross performance. In watches, this comparison with a machine is not entirely valid, and is in fact inadequate, since in manufacturing a watch these unfavorable circumstances increase immeasurably even with a moderate reduction in size. For example, a model of a large machine, such as a locomotive, built to 1" scale may still function adequately. On the other hand, a lady's automatic watch constructed on similar lines to a man's watch will not give as satisfactory a result. The performance of the automatic winding mechanism for the lady's watch would require improvement by the introduction of new principles.
The basic movement of the ETERNA-MATIC: The actual movement of the lady's ETERNA-MATIC model is circular with a diameter of 7-3/4 lignes (17,5 mm) and is of special construction with direct drive for the sweep-seconds hand. Apart from its other uses, this hand assures the wearer by a single glance at the dial that her watch is going. The public, and even some people in the trade, still have misgivings about the sweep-seconds hand, since they harbor the notion that such watches are less reliable. As a matter of fact, the chances of interruption are somewhat greater with an indirectly operated seconds hand than in a movement with either a small seconds hand or without one, because the indispensable brake spring places an additional burden on the movement. In the new style ETERNA-MATIC movement, the brake spring and the sweep-seconds wheel over the third wheel are omitted and the very large and easily controlled train of this special arrangement ensures a more certain operation of the movement than one with a small seconds hand. The balance wheel of the ETERNA-MATIC is mounted on a shock-proof assembly and is thus protected against injury from rough handling.
Construction of the automatic mechanism
In producing the automatic parts of the ETERNA-MATIC movement, the aim was to restrict to the minimum the increased bulk due to the winding train. Advantage was taken of the additional height required for the center-seconds train illustrates the relation of height. Thus, the wheel disc of the third winding wheel rests a little below the surface of the seconds-wheel. The automatic mechanism was successfully constructed as a self-contained unit to facilitate separation from the basic movement. The automatic bridge shaped like a three-quarter plate is attached to the barrel-bridge and the train wheel bridge by two pins and three screws which arc easily removable. The automatic bridge carries the complete automatic winding mechanism except those parts necessary to the basic movement itself. The oscillation axle is mounted on the side of the automatic bridge. The automatic reversing gear is secured through the head of the oscillating weight and turns easily on its pin. The automatic bridge also contains the bushings for the upper pivots of the second and third winding wheels. A small flat supplementary bridge is screwed from below to the automatic bridge. The supplementary bridge has a slender pin on which is set the bored pinion of the first winding wheel as well as a bushing for the lower pivot of the seconds wheel, and on account of the supplementary bridge remains in position when the automatic mechanism is detached. A bushing is provided for the lower pivot of the third winding wheel in the barrel bridge.
Here are some photos and ads for Eterna/Eterna-Matic watches over the decades:
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