Swissonic #41, Prototype

CEH – Swissonic #41, Prototype, 1967

Categories: functional prototype

Description: Stainless steel cased prototype. Silvered brass dial with raised 5 minute markers. White peripherial border with black printed minute marks. Black printed ‘Swissonic’ at ‘9’ and ‘Swiss Made’ at 6′. The prototype number ’41’ is embossed on one of the surfaces facing the lugs. Date window at ‘3’. Silvered, thin hour, minute and seconds hand. Acrylic crystal. Anonymous stainless steel crown.

Dimensions: 36.2mm (without crown), lug – lug: 41.3mm, lug width: 18mm

Movement: Prototype cal.: 153 (fragmentary)

Additional info: This is the earliest known ‘CEH – Swissonic’ prototype of cal.: 153. The movement is incomplete, most probably due to cannibalisation of the pieces for optimising other, later prototypes. The adjustment devices on the arms of the tuning forks are excentric screws, as seen on the patent of 1964/5, later the adjustment will be simplified using press fitted, metal hooks.

Case was made by ‘Taubert Fils’, who still used the mark ‘FB’ for François Borgel, who invented this type of watch case. The main case is unmarked, the ‘FB’ mark being stamped on the inside of the screw down case back, which is lacking in this piece.