The earliest timekeepers powered by a coiled mainspring date from the late 15th century but neither the remnants that have survived, nor the written sources, give precise information as to when the first portable timepiece was made and by whom. The same is true of the history of the fusee, as is illustrated by the present lot. There is a general consensus that the oldest surviving clock with fusee is the one belonging to the Society of Antiquaries, made before 1518 by Jacob Zech, a Bohemian clocmaker from Prague, for the Polish king Sigmund the Great. The fusee, one of two major power-equalizing devices, had been known for at least half a century before the creation of Zech's clock. In Leonardo da Vinci's Codex I, there is a sketch of a mainspring with a fusee accompanied by Leonardo's commentary describing it as the standard practice at the time (1492-97). The second power-equalizing device, the stackfreed, also appears in Leonardo's Codex I, as well as Codex M3 (1497 and 99) and mayhave been brought to his attention by his German assistant, Giulio, around 1493/94. Stackfreeds are present in surviving examples from about 1530-1640.Small timepieces first appeared at the end of the 15th century. There are records clearly indicating that they were known before 1510 both in Italy and in Germany. The present lot has all the characteristics of a German watch, except the fusee. The iron movement, lettering, and hog's bristle of the present watch suggest Germany as place of origin.However, the earliest German clocks did employ fusees. It appears that when miniaturization led to a reduction of the room between the plates, especially in case of complicated watches, the Germans invented the stackfreed to save space. However, when there was ample space, they did not mind using the fusee."Archeologia", Vol. XXXII, pp. 8-35, by Capt. W. H. Smyth, Director, London, 1848"The Manuscripts of Leonardo da Vinci Codex I", New York, 1974."The Unknown Leonardo", edited by Ladislao Reti, New York, 1974, p.253.Since the 19th century, experts on horology have speculated as to the original finish of the steel parts in early watches. Several theories have been advanced.1. That the steel parts were 'tinned' - coated in tin or lead to resist corrosion - and indeed there is record of at least one clock showing signs of having been originally treated in this way.2. That the movements were left with a fine filed finish - a finish that would be susceptible to rusting relatively easily upon exposure to moisture.3. That the plates were scraped or burnished to harden and compress the surface in order to resist rust . It seems likely that all three techniques were variously employed. Since it is quite usual to find a variance in the quality of finish on virtually identical cases of this period, the same would likely be true of the movements. Burnishing the exposed surfaces of any metal does indeed improve its resistance to corrosion as well as improving the finish.According to an expert who examined this watch two decades ago, the plates, although dull, were in remarkably good condition. However, when a cock was removed, the spot under it was shiny. He concluded, as well as the new owner, that the entire piece had been burnished to prevent rust deterioration. When the new owner gave the watch to be cleaned, he specified that it be restored to the same degree as found under the cock.