What is a Minute Repeater?A minute repeating watch tells the time both visually and audibly. A slide on the side of the case, usually near the #9, will activate two hammers in the movement. These hammers strike two gongs curled within the case. First one hammer strikes a gong of lower tonality; it will count out the hours. Then both hammers will strike both gongs alternatively to count out the quarter hours after that hour, and then the second hammer alone striking a gong of higher tonality will count out the minutes aftr that quarter hour. The repeating mechanism was developed by Daniel Quare. In 1687, he had patented a mechanism that sounded the hours and the quarter hours. The early repeaters used bells. At theend of the 18th century, two bent-wire gings became the more popular mechanism. In 1892, the first minute repeater wristwatch was produced by Omega, a model with a round-shaped case.What is a Perpetual Calendar?Mechanical movements tell time by means of ratcheted wheels turning in synchronization. The number of teeth on each wheel describes its function. There are separate wheels for the seconds, the minutes and the hours. A perpetual calendar movement has additional wheels, levers and springs. It has wheels for the days of the week, the day of the month, the year, usually one for the phases of the moon and usually one that makes just one revolution every four years, synchronized with all the others, taccount for February 29th in the leap year. Audemars Piguet said they produced the first wristwatches with the perpetual calendar and moon phases in 1924. In 1925, Patek Philippe modified a lady's pendant watch with perpetual calendar to produce the world's first instantaneous changingperpetual calendar wristwatch with indication for leap years.