Omega Observatory Chronometre, Cal. 60.8

Although it may not have been clear at the time, the quest for mechanical timekeeping ended 40 years ago. This is not to say that all progress has stopped, or that the market has forsaken mechanical timepieces, but rather that by the late 1960s alternative means of marking time were several orders of magnitude more precise, and rapidly becoming similarly inexpensive. Today, advances in machine precision, metalurgy, lubricants and material science allow manufactures to produce movements which predictably surpass COSC specifications without costly adjustment, and which often run acceptably for many years with little attention. Water and dust resistance are much improved, cases, dials and hands are more durable...functional quality at all price points is undeniably better. It's a good thing, too, because out at the far end of the curve, today's watches, as timekeepers, hardly best their mid-20th-century ancestors, if at all.

Historically, by the mid-1700s the basics of modern mechanical timekeeping were already in place. Christian Huygens had created a balance-spring regulated watch, and Thomas Mudge the Swiss-lever escapement, and in 1764 John Harrison's three-pound H4 marine chronometer was keeping time accurately within two seconds per day, for months at a time, out on the open ocean. For the next sixty years the inventions of Abraham-Louis Breguet dominate the development of what we now call pocketwatches, and soon many individuals and firms were capable of producing portable timepieces providing admirable accuracy and precision.

Eventually watch manufactures began submitting a few of their best watches for competitive testing at astronomical observatories, providing an arena to publicize their products and promote scientific progress. Chronometer testing and certification began in Neuchatel in 1866, and Geneva in 1873, and ended in Neuchatel in 1975, and Geneva in 1967, wounded first by the success of entries from Seiko, then finally deemed irrelevant with the growing affordability of quartz-controlled watches.

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The Swiss competitions classified entries according to movement size, in consideration of the obvious advantages of a larger mainspring and balance, and the relative ease of manipulating and maintaining larger parts. The largest watches were those of Category A, being up to 70mm diameter, thus accomodating marine deck chronometers. This was also the home of most watches designed solely for their timekeeping ability, as technical test platforms and demonstrations of their manufacturers' accomplishments. Certified watches demonstrated accuracy and consistency according to variable positions and temperature, as well as state of wind (isochronism) and over a period of nearly seven weeks. Omega was among the most active competitors, and its successful involvement is wonderfully recounted by Michael Ting, Melvyn Teillol-Foo and Suitbert Walter in this posted article.

The present watch was tested from March 31 through May 15, 1930. As its Caliber indicates, the movement is 60.8 millimeters diameter, so it would have been entered into Category A as noted above. Never intended for any commercial use, Omega produced only 88 examples, between 1925 and 1930. Despite its entirely utilitarian intentions, the 60.8 carries its own stark beauty. At the front, it shows a pristine white fired-enamel dial with stylish hand-painted numerals and lovely blued-steel spade hands.

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Details of the dial, and sunken small-seconds subdial:

Aesthetically, this movement is the antithesis of decorative design. Geneva stripes, bright red sapphires, gold chatons, blued screws and pigmented engraving are all absent. Instead there is only the serenity of plain frosted German silver bridges, polished screwheads, and clear jewels neatly countersunk, each offering a glimpse of the shaft and gears below:

This view shows the blued-steel overcoil hairspring and Guillaume alloy balance with gold adjusting screws. The balance can be distinguished from a normal split, bimetallic balance by the relatively long 'tail' between each arm and cut rim. While an ordinary bimetallic balance will help compensate for timing errors at high and low temperatures, a Guillaume balance does so with much less distortion at ambient temperatures:

Brushed steel cap for the clear pallet jewel, fantastic sculpture of the polished and brushed anchor, delicate escape wheel:

Stud carrier (right) and the business end of the regulator (left), along with a closeup of that ultra-blue spring. The purple hand attached to the end of the balance staff can be used to judge the amplitude as it swings back and forth, and hides a single colored sapphire:

The front page of the Chronometre certificate describes the movement by serial number, diameter, balance and escapement details, and manufacture, and provides this summary of performance:

Average daily rate: +/- 0.13 seconds
Temperature deviation: -0.013 "
Secondary error: +/- 0.18 "
Variation periods one and ten: + 1.30 "
Positional deviation: +/- 0.38 "

Daily measurements report performance at three vertical and two horizontal postions, and three temperatures, over a period of 45 consecutive days:

The chart at upper right lists the average performance for each of the ten periodic examinations by position and temperature, and then below provides the results by temperature alone:

This is a watch unlike any you will encounter in the street, a special machine justified only by its exceptional timekeeping and as proof of its makers' sincere dedication to the art and science of horology!

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May 1, 2007

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