A 20th century Swiss Atmos 'clock' the dial and movement signed and numbered LeCoultre & Cie Calibre 528-8 Serial number 276676A 20th century Swiss Atmos 'clock'the dial and movement signed and numbered LeCoultre & Cie Calibre 528-8 Serial number 276676the rectangular case with lacquered brass framework sunk into the substantial chamfered polished base, the latched door opening to allow for case height adjustment using the integral spirit level, the white and brass Arabic dial with skeletonised centre bearing two counterpoised brass hands, the exposed movement with delicate jewelled train and Elinvar wire, terminating in an indexing platform with 'SF' and 'RA', 24cm high This calibre, 528-8, was manufactured between 1960-1980. The serial numbers in 1960 began with 107,001 and it has been suggested that LeCoultre were manufacturing up to 25,000 Atmos' per year. If this was the case, it would suggest a date of manufacture of around 1967 for the current clock.Walliman, A. (2017) Dating Your Atmos Clock. Available at: http://atmosclocks.com/dating.html. Polish Gemmalogical Labratory (2019) Jaeger-LeCoultre Clock, Atmos 528-8. Available at:http://www.antyki.podgryfami.pl/katalog/zegarki/stolowe/zegar-jaeger-lecoultre-atmos-528-8.html?hl=en.