he Portuguese Sidérale Scafusia is the most exclusive and complicated mechanical watch ever made by IWC. It took the project team at IWC Schaffhausen 10 years to develop and build this spectacular masterpiece. The dial, in the style of a classic Portuguese, features a constant-force tourbillon together with displays for the 96-hour power reserve and sidereal time. This deviates from normal solar time by just under four minutes each day and, among other things, is needed if we wish to find the same star each night in the same position. The reverse side of the Portuguese Sidérale Scafusia is a fabulous astrolabe calculated precisely to reflect the owner’s wishes. From a previously defined location, the rotating night-sky disc shows more than 500 stars and constellations with such detail and precision that it would quicken the pulse of any astronomer. Making the necessary allowances for summer time and winter time, the watch also displays the times of sunrise and sunset, sidereal time and a perpetual calendar with the leap years. In view of the enormous amount of work involved and the more than 200 individual configurations possible, only a few watches are produced each year.
