The Perpetual Calendar is perhaps the most intellectually astounding. A mechanism of breathtaking complexity, it accurately displays the date, day, month, and even leap years, accounting for the varying lengths of months until the year 2100 (when a secular-year correction is needed). It is a mind of its own, a mechanical brain that understands the quirks of our Gregorian calendar.
The Minute Repeater is the most sonically sublime. At the push of a slide, tiny hammers strike coiled gongs inside the case, chiming the time in hours, quarters, and minutes. It is not a alarm; it is a melody. The development of a minute repeater with a clear, resonant, and harmonious chime is one of the most demanding challenges in watchmaking. To hear one is to hear music born of mechanics.
