A Swiss 18K gold single button chronograph watch Circa 1900

Gold open faced keyless chronograph by Patek Philippe & Co.
–
A Swiss yellow gold open faced keyless single button chronograph watch with a 30 minute register, circa 1900. The watch features a mechanical, jewelled lever movement. The white enamel dial displays radial Breguet style numerals, an outer 1/5th seconds track with Arabic numerals for five seconds, subsidiary dials for seconds at 6, a 30 minute register at 12, and blued steel spade hands. It has an 18 carat yellow gold polished case with a cuvette and a snap-on case back. The case, dial, and movement are all signed. The watch is accompanied by a Patek Philippe Certificate of Origin and a presentation box.
–
Diameter: 50 mm
–
Signed: Patek Philippe & Cie, Genève
–
The movement is in working condition, and the chronograph function operates properly. The enamel dial is clean and intact. The case shows minor surface wear, with pinhead dings in places. The hinges are nice and tight. Otherwise, the watch is in very good condition, considering its age.