215,750 CHF
SILVER OBSERVATORY “TOURBILLON” Omega, Usine de Geneve "Tourbillon", No. 10595936, Cal. 30 I. The 4th of 12 movements made in 1947, then entered in the 1948 Geneva Observatory trials, where it scored 806 points and again in 1952, where it scored 735 points. One of seven movements cased and sold in 1987. Extremely rare and very important, sterling silver gentleman's wrist chronometer with a 7 1/2 minute Tourbillon regulator. This watch is sold with a box, Certificate of Authenticity and 2-year Omega guarantee. Matte silver with painted black Dauphine numerals, outer minute divisions and subsidiary seconds dial. Blued steel “baton” hands. Notes Guillaume Balance In 1899, Dr. Charles Edouard Guillaume noticed that steel with an addition of 44.4% nickel had a negative square coefficient of thermal expansion. This alloy, combined with brass in bimetallic lamina, makes its expansion close to quadratic. Balances with bimetallic rims made of anibal (anibal, an alloy invented by Guillaume, stands for Acier au Nickel pour BaLanciers) and brass are usually called Guillaume balances, or, as their inventor called them, integral balances. When combined with special balance springs, they exhibit remarkable temperature stability, on occasion not exceeding 1/50 second per day at 1ºC.
Auctioneer:
Antiquorum
Date:
2007-04-15
