In 1948, Patek Philippe inaugurated its Electronic Division with the aim of researching photoelectric, electronic and nuclear technology to power clocks. Within two years, the department succeeded in creating its first solar clock. The caliber 17-250 was fitted with a small rotatable solar panel on the top of the dome supplying energy to a storage device, which in turn transmitted energy to the mechanical movement. A Swiss patent was awarded to Patek Philippe for clocks fitted with photo-electric cells. Patek Philippe's idea for a light-powered horological mechanism was to introduce additional electronic storage – an accumulator that provides the energy to wind the spring. The photoelectric cells can either store their energy electronically in the accumulator, or mechanically by winding the spring. When the mechanism is fully wound, the cells switch over to charge the accumulator.

This striking and attractive dome clock is decorated with a cloisonné enamel scene depicting the theme "Portugal". A unique piece based on Portugal's Great Discoveries, each panel displays an ancient map that depicts Portuguese territories at the time of the signing of the Treaty of Tordesillas in 1494. Gold ribbon indicates the lines of longitude, such as the Equator, the tropics of Cancer and Capricorn. Furthermore, the clock is engraved "Portugal Peça Única, 25th Aniversário da David Rosas." Made to commemorate the 25th anniversary of the retailer, this clock was originally auctioned at the "Patek Philippe Genève Auction" on February 25, 2010, where all profits were donated to the charity institution "Terra dos Sonhos". Furthermore, the watch is accompanied by a Certificate of Origin dated November 9, 2010 that is also stamped by the retailer.