Yes, the plural has to be used, as there were different Geomatics, made since 1962 to 1970 ( round cases ) and from 1970 to 1974 ( tonneau shaped case ) for a total of 4351 round cases produced ( 2000 in stainless steel, 1578 in yellow gold, 773 in rose gold ) and 410 tonneau cases ( 60 black dials, 250 champagne, 100 white ).
- The round Geomatic:
There are two references: E 398 ( yellow and rose gold cases ) and E 399 ( stainless steel ).
Two references, as yes, the gold and the stainless steel cases are different.
The stainless steel with these characteristic long beveled lugs, and the slightly domed silver dial:
The typical case back:
The gold versions, with different dials:
The very sophisticated linen dial:
This is not an exhaustive list of dials, as a few others existed.
But you can already notice that the lugs are very different, on the gold cases.
The gold and the steel versions, side by side, recto and verso:
The case is 36 mm big, for a height of approximatively 9 mm.
The screw in case back is showing a very nice medal, with the famous sphere, reminding the Geophysic Logo.
As for the movement, it is the Cal 881 or 883, a 23 jewels automatic movement, with a rotor instead of the bumper, adjusted in five positions and temperatures, beating at 19800 vibrations per hour.
It has a kif shock protection and a stop second. It has been tested during 360 hours, and is, therefore COSC certified.
It is 25, 99 mm big, and 6, 17 mm high.
The round Geomatic is certainly the finest JLC Chronometer, at least when we compare the case, and especially the E 399.
- The Geomatic " Tonneau " Ref E 560:
Sign of the times, with the E 560, we are in the Seventies. As original as it is rare, the elegance of the round case let place to funky lines.
The movement is the same, the Cal 881 or 883, as well as the case back, which is screwed in, with the Sphere.
I saw the black dial only once, and in picture...
If you are fan of the funky trend, wait to see the Cal 906, in the next and last part.