Ref. 1416 Only three examples of this watch are known to exist and they are characterised by the use of straight "claw" lugs. A similar watch is published in Patch Philippe Wristwatches, by Martin Huber & Alan Banbery, Edition 1998, p. 244. Patek Philippe "World Timers" The "World Time" system was invented around 1935 by Louis Cottier (1894-1966), famous independent watchmaker in Geneva. This "World Time" system was used by Patek Philippe and also by other major names in the Swiss watch industry, such as Agassiz, Rolex and Uacheron Constantin. Patek Philippe created various series of "World Timers" and the earliest known is a probably unique rectangular "galbe" pink gold model, Ref. 515, made in 1937, which was sold by Antiquorum, Geneva, April 10, 1994, lot 502, for SFr. 550'000 (US$ 388,560) . From 1937 until about 1940, Patek Philippe used the "World Time" movement in various types of cases: Ref. 542 (0 28 mm.), of which only 4 examples are known to date and three were sold byAntiquorun: - Geneva October 17, 1993, lot 431, at SFr. 121'000 (US$ 81,700) - Geneva, October 15-16, 1994, lot 608, at SFr. 110'000 (US$ 87,300) - Geneva, April 10, 1994, lot 500, at SFr. 231'000 (US$ 164,200) with unusual bezel and hands. Ref. 96 "Calatrava", which appears to be an unique example, made in 1939. Around 1939-1940 began the production of the series Ref. 1415 (drop-shaped lugs), together with three examples of the Ref. 1416 (straight "claw" lugs), both references with a diameter of 31 mm. and on the revolving bezel the names of 30 cities of the world. hs 1940, Patek Philippe created, specially for Dr. P. Schmidt, a unique "World Time" chronograph ( Ref. 1415-1) wristwatch, in yellow gold, with square push buttons and the names of 33 cities of the world, which was auctioned by Antiquorum, Geneva, October 15-16, 1994, lot 516, setting a World Record at SFr. 990'000 (US$ 785,714). This watch is illustrated on the front cover and p. 270 of the new edition (1998) of Pack Philippe Geneve, Wristwatches, by Martin Huber & Alan Banbery. From 1940 onwards, Patek Philippe produced "World Timers" in three main series which include chess watches (Ref. 605, circa 1940- 1960's), some with a matt silvered dial and others with a cloisonne enamel dial; and, wristwatches, with one crown (Ref. 1415, circa 1939-1950's), and two crowns (Ref. 2523 and Ref. 2523-1, circa 1953-1965), some with a matt silvered or gilt dial, some with a guilloche dial, some with an enamel dial and some with a "cloisonne" enamel dial. "World Time" Patek Philippe mismatches are published in Patek Philippe Geneve, Wristwatches, by Martin Huber & Alan Banbery., 1998 Edition, pp. 240 to 247.