This Invar gold pocket watch was made in Switzerland in 1915. The watch is in very good condition and excellent working order, having been fully revised, cleaned and adjusted in order to guarantee its good performance. The watch’s box is made of gold with hallmarks . The front cap is made of glass and protects an elegant white face with black Arab numbers and filigree hands. The face bears the word INVAR printed at the top. The Invar watch company was founded in 1901 by Achille Hirsch in La Chaux de Fonds, Switzerland. The word ‘invar’ is actually the name of a metal alloy notable for its relative lack of expansion or contraction with temperature changes. It comes from the word ‘invariable’ and was discovered in 1896 by Charles Edouard Guillaume, who received the Nobel Prize of Physics for this discovery. Achille Hirst registered the trademark to distribute watches with invar balance wheels in their movements. This way, anyone who bought an Invar watch could be sure that the movement was a quality one. On the other hand, Hirsch was a very prolific watch distributor who registered hundreds of trademarks. If you have any questions,pleace ask befor you bought the ithem.