Previously in the the collection of the Time Museum, Rockford, Illinois, U.S.A., it is described by Anthony Randall in The Catalogue of Chronometers in the Time Museum,, page 86, entry No. 18. It was sold by Sotheby's in New York on 11 December 1986, lot No. 186. Originally made with the typical Louis Berthoud's pivoted detent escapement, the escapement was replaced by a spring detent escapement toward the middle of the XlXth century, but the original escape wheel was preserved. Founded in 1875 by Jules Audemars and Edward Piguet, both already master watchmakers, as were their fathers and grandfathers, the company's workshops still located on the original site in Le Brassus in the Vallée de Joux (in the Swiss Jura mountains), heartland of fine Swiss watchmaking. Audemars Piguet's commitment is to excellence and creativity in traditional mechanical watchmaking. It specializes in "complicated" wristwatches, those which perform a number of complex time-keeping functions by means of a slim automatic movement. AII its individually numbered and signed watches are entirely hand assembled, each by a single master watchmaker, who personally selects, refines and hand-polishes every tiny element of a watch, sometimes more than 600 of them. The company's philosophy has been handed down from generation to generation of master watchmaker's in Le Brassus: "Beauty lies in pure, uncluttered lines," Edward Piguet. "Always innovate, always excel", Jules Audemars. And the company, over more than a century, has continuel to innovate and to excel. master watchmakers have always seemed to be just a little ahead of their time. In the Jumping Hour and Minute Repeater wristwatches of the 1920's and 1930's. In the development and refinement of mechanical and automatic movements to their present position of pre-eminence in fine watchmaking. In the elevation of steel to the status of a precious metal in the sensational announcement of the first-ever Royal Oak, presented uniquely in steel at the Basel fair of 1972. The masterwatchmakers of Audemars Piguet constantly set themselves new challenges. In this year's Basel Fair, several have been met and conquered. The Jumping Hour and Minute Repeater mechanisms have been united for the first time ever in a movement only 5 mm thick. The Royal Oak, a watch whose distinctive octogonal bezel has become a fashion icon, finds its roots again in the Royal Oak offshore: water-resistance increased to a full 10 atmospheres, 1/5 seconds chronograph, lapsed time counters and tachymeter. The triple complication is a miraculous miniaturisation of the historic "Grande Complication" into wristwatch form. While at Le Brassus, Audemars Piguet is building a History of Watchmaking museum around the two senior watchmakers-masters among masters, who each year make one "Grande Complication", the magnificent pocket watch which is the original source of Audemars Piguet's present worldwide success. First presented at the Paris Fair in 1889, composed of over 400 tiny pieces, it displays the day, date, week, month, phase of the moon, chronograph with flyback hand, chimes the hours, quarters and minutes on demand, and there is still a waiting-list of several years.