ID 1163618
Lot 4151 | Pocket watch: technically highly interesting chronometer, "si…
Valeur estimée
€ 2 000 – 5 000
Ca. Ø52mm, ca. 138g, solid silver case, Hallmarks London 1864, original watchpaper, signed John Reid, extremely rare chronometer movement "sidereal time chronometer No. 500", detent chronometer escapement, chronometer balance with gold screws, helical hairspring, diamond endstone, key winding, signed, No.500, original enamel dial, signed and numbered No.500, blued steel hands, in working order, extremely rare. Only very few pocket chronometers were so-called "sidereal time chronometers". Sidereal time is also a true time, but in contrast to solar time, it depends only on the rotation of the Earth. In every astronomical observatory there is a pendulum clock or sidereal time chronometer regulated to sidereal time, so that sidereal time can always be read there. Regulating pendulum clocks or chronometers in sidereal time is the responsibility of chronometer makers or specialists, as electronic measuring instruments cannot be used for this purpose. A sidereal day is the length of one rotation of the Earth, measured from one culmination of a star to the next. It is essentially the same length on all days of the year; there are only minor influences of nutation and precession, but these are only significant for astronomers. A sidereal day is 23 h 56 min 3.44 s long, so it is 3 min 56.56 s shorter than a mean solar day. The sidereal year has 366.2422 sidereal days, one day more than a solar year. A sidereal day is also divided into 24 h of 60 min of 60 s each, which are all correspondingly shorter than solar hours, minutes and seconds. Source: (https://www.cortrie.de/go/rr9).
| Catégorie maison de vente aux enchères: | Montres de poche |
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| Catégorie maison de vente aux enchères: | Montres de poche |
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| Adresse de l'enchère |
Karl-Heinz Cortrie GmbH Süderstr. 282 20537 Hamburg Allemagne | ||||||||||||||
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| Aperçu | |||||||||||||||
| Téléphone | +49 (0)40 21906520 | ||||||||||||||
| Fax | +49 (0)40-219065229 | ||||||||||||||
| Commission | 23.8 | ||||||||||||||
| Conditions d'utilisation | Conditions d'utilisation | ||||||||||||||
| transport |
Service postal Service de messagerie ramassage par vous-même | ||||||||||||||
| Modes de paiement |
Virement bancaire | ||||||||||||||
| Heures d'ouverture | Heures d'ouverture
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