Swiss rare double sided chronograph pocket watch Circa 1906

Chrono-Tachymeter Cadran Brevetè S.G.D.G. by Omega
–
An extremely rare Swiss double sided Omega tachymeter chronograph “Chronotachymètres” with Omega patent no.8760 from 1906.
Nickel case, both sides glazed. Face with time indication, Roman and Arabic numerals, centre chronograph hand, special chronograph with Cadran Breveté S.G.D.G tachymeter dial and 5 different-colored register and 15 min register. Another chronograph on skeletonized back, movement with fine adjusting device and chronograph, silvered ring with tachymeter scale up to 180km/h.
–
Diameter: 58 mm
–
Weight: 143 g
–
Signed: Omega
–
This Omega double chronograph is extremely rare. A detailed description of this rarity can be found in the catalog of the special auction “OMEGAMANIA” 2007 Geneva, Lot 71. The Cadran Breveté S.G.D.G tachymeter dial enabled the direct reading of all speeds between 10.5 and 140 mph without counting. 15min counter starting with 5 different coloured minute segments as an indication on which colour the speed can be read.