Nine years ago, in a piece in the BHI’s Horological Journal, Derek Pratt FBHI set out a history of double-wheel escapements. The article encapsulated many ideas and approaches, from Breguet’s échappement naturel, to Daniels’ Independent Double-Wheel and Co-Axial Escapements, and described Derek’s own work to further develop these ideas into the Soluthurn* pocket watch in 1997. …