This watch is published in 'Patek Philippe Genève, Wristwatches', by MARTIN HUBER and ALAN BANBERY, PatekPhilippe S.A., Geneva, 1998, p. 278, fig. 430.Patek Philippe wristwatch 'à guichets'As a result of our meticulous and lengthy research on this important wristwatch, it would appear that this model wasmade with American type calendar (indicating clockwise, first the day, then the month, and thirdly the date). The presentwatch has this type of calendar but with French months and days which would indicate that it was then sold to a personwho wanted the calendar in French. We can quite safely assume that this is an extremely rare model and probablyexecuted in one example only.What is particularly surprising in this watch is the design of the dial and the concept of the movement, both in terms oftechnique and iconography. It is in fact most unusual for Patek Philippe to produce watches with simple calendars,seeing the firm's predilection for more complicated watches. The few known examples with these characteristics, andcontemporary to the present watch, have however only two apertures, with the indication of the days of the monthsconcentric on the outer part of the dial. Two other examples are known, but with only two 'guichets'.As horological experts, we are also aware of the technical difficulties involved in producing a perpetual calendarwristwatch with three 'guichets', placed so far away from each other on the dial. In this particular example of simpletriple calendar, the positioning of the three 'guichets' on the dial creates a remarkable geometrical harmony. This canonly be a choice made on a purely aesthetical basis, rather than having been dictated by technical reasons.What is particularly impressive in this watch model is the soberness of its dial, created at a time when watch designtended to show the various functions with superposition of hands and scales and the movement's complications, even ifreading the dial was made more difficult.Such unique characteristics lead us to think that this was an experiment on the part of Patek Philippe to create a moreavant-garde design, probably inspired by the Modernism movement in architecture of the beginning of the 1930's. Thedesign of this watch dial evokes also the evolution of the Art Deco period, from which was later derived the developmentof all modern design.CalatravaFor more than sixty years the Calatrava has been considered a classic and the most popular wristwatch, even thoughits production is limited to a few thousand pieces per year, since it takes about nine months to complete one watch.Patek Philippe, which initially specialized in custom-made watches, launched its first collection in 1932, with thecreation of the Calatrava. This wristwatch collection for gentlemen derived its name from the knight's cross, symbol ofthe Geneva manufacturer. Over the years, several variations were created. Some cases are endowed with straight lugsfrom which the strap is assembled, others have integrated lugs that flow harmoniously and produce a 'tonneau' effect.