The watch appearing in the background on the GearTrains home page is a well preserved example of the work of Abraham-Louis Breguet, a Swiss widely regarded as the greatest watchmaker who ever lived, who settled in Paris in the late 18th century and worked there into the early 19th. See  and  for professional biographies of A.-L. Breguet. Perhaps 200 watches per year were produced at his firm’s peak during his tenure, with no two exactly alike. Breguet’s customers included both Marie-Antoinette and Napoleon Bonaparte. The Breguet firm exists to this day, building fine watches in the spirit of its founder. Also, the Breguet archive, containing the company’s business records back to its founding, still exists in Paris as a part of the Breguet Museum. The Museum will examine a timepiece brought in for authentication and compare it with the company’s records. If it is a genuine Breguet, the Museum will offer to issue a certificate so stating for a reasonable fee.
Among many other innovations, complications, and improvements, A.-L. Breguet invented the so-called "parachute" suspension for the balance shaft of watches, the first effective shock-mounting; the tourbillon, a slowly rotating frame containing the balance wheel and escapement of a watch used to average out the varying effects on an escapement's accuracy as its orientation is changed with respect to the direction of gravity; and devised the first practical self-winding mechanism for pocket watches, a weight at the end of a horizontal shaft supported by a spring. For the last of these, as the wearer walked, the weight would bob up and down, causing a ratchet to wind the watch. We have seen a pedometer made early in the 20th century which works quite nicely on the same principle, though with a considerably lower quality of materials and finish than Breguet would have produced.
The background watch is No. 1734 by A.-L. Breguet. Its serial number and other
evidence suggest that this watch was made about 1808, but its recently-issued
certificate from the Breguet archive indicates that it
was first sold on 13 March 1814, to the Duchess of Newcastle. The porcelain dial,
shown in Figure 1, is unmarred except for a few faint scratches around the shaft (visible only under magnification) where the key slipped while setting the time. Breguet, whose watches were faked even during his lifetime, authenticated his watches with a "secret signature" on the dial of each. On porcelain dials these would comprise the watch number and "Breguet", both in tiny script scratched into the dial below the 12. Making these signatures required tools and skills which would present a severe challenge even today. Seeing the signatures requires a jeweler's loupe and strong light at precisely the right angle; the dial of this example is marked "No. 1734" with a script "Breguet" underneath.
The case, shown in Figure 2, is in rose gold with an eccentric engine-turned design engraved into the back as decoration. The edge of the case is reeded (milled like a coin edge) inset below the edges of the case back and the bezel for the crystal. The entire case is in nearly-new condition. Breguet No. 1736, pictured in a sale catalog , is substantially identical in appearance, except for the decoration on the case back.
The inside of the case back is in pristine condition. The cuvette, Figure 3, is
elegantly engraved with the watch's number and maker's name, together with
an arrow around the winding hole to show the direction of winding. It is blemished a bit by the expected key-scratches around the winding hole. In Figure 4, it can be seen that the inside of the cuvette has had an end mill applied delicately to provide clearance for the balance shaft end and three other high points on the movement.
References: Breguet, Emmanuel; “Breguet, Watchmakers since 1776”, Alain de Gourcuff and Breguet S. A., Paris 1997. This beautifully produced, large-size book is a general history of the Breguet firm published by the firm itself. About 2/3rds of its roughly 380 pages are devoted to the professional life of A.-L. Breguet. There are many lovely, full-color photographs of Breguet timepieces and other illustrations.
 Salomons, Sir David Lionel Bt.; “Breguet. (1747 - 1823)”, published privately by the author, London, 1923. After a brief professional biography of A.-L. Breguet, lists and descriptions of several Breguets are given, followed by black-and-white photographs of over 100 A.-L. Breguet watches and clocks in Salomons’ collection. This book was published in both English and French. The French edition, published after the English, contains corrections and additional material, and is therefore more desirable. A pamphlet in English containing this additional material was also published, and is occasionally found separately or together with a copy of the English edition.
 "The Art of Breguet", the catalog for an auction of Breguet timepieces held on 14 April 1991 at Hotel des Bergues, Geneva, Switzerland by Habsburg Fine Art Auctioneers, p. 132. This beautifully printed and bound hardcover volume contains extensive descriptions and some histories of the items offered. This catalog is not to be confused with the marvelous book of the same title by George Daniels.
 Daniels, George; "Watchmaking", Philip Wilson, London, Revised Edition 1991. This remarkable volume was intended by its author, one of the very few people on the planet who can design and make a complete watch, including movement, dial, and case, to provide instruction in his highly exacting art. Chapter 8 on escapements exhibits unmatched practical knowledge and deep understanding of this demanding subject.