The Longitude at the Eve of the Third...

Geneva, Hotel Des Bergues, Oct 23, 1999

LOT 178

Phonotélémètre Thouvenin, Breveté S.G.D.G.,No. 2042, circa 1900.Unusual chromium plated keyless watch with chronograph, 15 seconds chronograph, sound telemeter, 15 minute progressive recorder, special kilometric map distance gauge and compass, recommended by the War Minister, officially adopted by the French Military Schools.

C. Three piece, "bassine et filets", a small compass set in the winding crown and small knurled wheel on the band for the distance gauge. D. White enamel on the front with Roman numerals, outer gauge scale calibrated for 20 km and inner for 15 km. White enamel on the rear face for the 15 seconds chronograph, inner red 5 kilometre telemeter ring and subsidiary minute register. M. 19''', gilt brass, three-quarter plate, 15 jewels, straight line lever escapement, cut bimetallic balance, Breguet balnce spring.Signed on the dial.Diam. 53 mm.