An interesting chronometer with rare resilient balance spring stud.  Molyneux was almost alone in using this device.  The British Museum has a full plate pocket chronometer movement by this maker employing the same resilient stud (Museum number 1958,1201.1608).  The section of the stud close to its foot is very thin, similar to that of the detent spring.  As the balance oscillates the fixing point of the balance spring is allowed to move sideways in relation to the balance staff.   This movement has little effect on the rate controlled by the length of the balance spring.  Its intention would appear to be to equalise the rate in the long and short arcs of the balance which is more usually compensated for by the terminal curve or Breguet overcoil.  Robert Molyneux was a maker of chronometers who was trained by Thomas Earnshaw.  After setting up business on his own he formed a partnership with his son, Henry, 1833 - 1842.  Casemaker Louis Comtesse, 10 East Street, Red Lion Square.