Antique Invar Grand-Prix Pocket Watch 18k Gold Plated Silver Enamel Skull Case

I am pleased to offer from my private collection this rare antique Invar lever Chronometer Grand-Prix gold medals winner pocket watch  c1910 in excellent original condition!

The watch has a luxury 18k gold plated and black enamel engraved silver case depicting a Memento Mori symbols-skull and crossed bones;a sand clock with wings.

The watch has the highest grade Invar caliber movement , lever chronometer , precision regulator,old style hand engraved balance cock,Invar balance,Breguet spiral,maximum jeweles.

Fine enamel dial with original gold hands.

Perfect working order,reacently serviced. 

History: The Invar Watch Co. was founded in 1901 by Achilles Hirsch in La Chaux de Fonds,named after the invar material used in balance. Invar was invented in 1896 by Swiss physicist, Charles Edouard (acute on ‘E’) Guillaume, but he was only internationally recognized for the discovery in 1920 when he received the Nobel prize for physics, encouraged by the improvement in scientific instruments that the use of Invar had allowed. Invar has proved to be an incredibly useful alloy and is used where high dimensional stability is required, such as precision instruments, clocks, seismic creep indicators, TV shadow-mask frames, valves in engines, and antimagnetic watches. I have not so far mentioned the useful antimagnetic properties of Invar, but in combination with high dimensional stability, these make for an excellent material to be used in the manufacture of hair springs and certain other components in mechanical watches. Indeed, the bi-metallic balance in watches that had been the previous method of controlling accuracy for temperature variations could now be replaced by solid Invar. It comes with a Certificate of authenticity and appraisal for $3000 Free shipping to worldwide by DHL overnight courier.