
Age determination of watches from 1700 onwards with "10 point rating" according to Schmeltzer
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Age determination of pocket and wrist watches
Bernhard Schmeltzer
Age determination of pocket watches according to the "10-point system"
1.) Check all 10 points in comparison with the antique clock and note the left and right year if they match.
2.) Cross out the 9 oldest numbers on the left and the 9 youngest numbers on the right.
The determined age of the watch being checked lies between the left and right remaining year numbers.
To ensure the clarity of the "10-point table," all technical features that are unrelated to the period of manufacture or are rarely encountered have been deliberately omitted. Pocket watch replicas produced after 1970 can be easily identified by their shock protection. Age estimates for watches with unusual escapements, special complications, or modifications can only be determined by an expert in antique watches.
The 10 test points:
Production period rounded to 5 years |
||
1. Elevator. |
Key lift |
before 1700 - 1885 |
Crown winding and side pushers |
1850 - 1930 |
|
Crown winding without side pushers |
1890 - present |
|
2. Temple shape (if crown winding) |
around |
1850 - 1910 |
oval |
1890 - present |
|
square |
1910 - present |
|
3. Inhibition. |
Verge escapement |
before 1700 - 1845 |
Cylinder escapement |
1790 - 1925 |
|
Pin lever escapement |
1870 - 1975 |
|
Chronometer escapement |
1775 - 1915 |
|
Pointed-tooth lever escapement |
1800 - 1900 |
|
Piston-tooth lever escapement (straight lever) |
1840 - 1900 |
|
Swiss piston tooth lever escapement |
1855 - present |
|
Glashütte piston tooth lever escapement |
1850 - 1945 |
|
4. Balance wheel (in conjunction with stone anchor) |
Balance wheel rim without screws |
1840 - 1885 |
Compensation balance, bimetal |
1820 - 1945 |
|
Monometallic balance with screws |
1875 - 1970 |
|
Balance wheel rim without screws (shock-resistant) |
1965 - present |
|
5. Spiral (in conjunction with stone anchor) |
Breguet hairspring (blue) |
1820 - 1945 |
Breguet hairspring (white) |
1920 - 1955 |
|
Flat spiral (white) |
1920 - present |
|
6. Pointer. |
hour hand only |
before 1700 - 1725 |
only hour and minute hands (verge clocks until 1845) |
1700 - 1775 |
|
Hour, minute and second hands (common after 1800) |
1750 - today |
|
Pointer very fine, thread-like |
1830 - 1880 |
|
7. Dial. |
Relief metal leaf, hour number ring or 12-hour enamel cartridges |
before 1700 - 1725 |
Relief metal dial, hour number ring and minute track 5, 10, 15 etc. up to 60 |
1700 - 1800 |
|
Metal dial, engraved |
1775 - 1875 |
|
Metal dial, silver-plated or gold-plated, without engraving |
1905 - 1945 |
|
Metal dial, lacquered |
1940 - today |
|
full enamel leaf, strongly curved |
1720 - 1810 |
|
full enamel leaf, slightly curved |
1800 - 1835 |
|
full enamel sheet, flat |
1825 - 1945 |
|
full enamel leaf, recessed leaf center |
1875 - 1925 |
|
colored enamel dial with floral painting and/or gold minute dots |
1875 - 1915 |
|
luminous material |
1915 - present |
|
8. Numbers. |
Roman numerals (without minutes) |
before 1700 - 1725 |
Relief metal dial, Roman hour numerals and Arabic minute numerals 5, 10, 15, etc. up to 60 |
1700 - 1800 |
|
full enamel dial with Roman hour numerals and Arabic minute numerals 5, 10, 15 etc. up to 60 |
1725 - 1800 |
|
full enamel dial with minute lines, hour numbers (or Arabic minute numbers 5, 15, 45, 60) |
1775 - 1830 |
|
full enamel dial with vertical Roman numerals |
1785 - 1815 |
|
fine thread-like Roman hour numerals and small Arabic minute numerals 5, 10, 15 etc. up to 60 |
1830 - 1880 |
|
Roman, normally proportioned hour numbers |
1875 - 1900 |
|
full enamel dial, flat, Arabic hour numerals |
1895 - present |
|
red hour numbers 13, 14, 15 etc. up to 24 |
1900 - 1925 |
|
9. Clock stones. |
framed |
1700 - 1945 |
pressed in |
1925 - present |
|
Shock protection |
1945 - today |
|
10. Special works. |
Pocket stopwatch |
1825 - present |
pocket chronograph |
1875 - present |
|
Repeating mechanism on bell |
before 1700 - 1820 |
|
Repeating mechanism on gongs |
1780 - 1940 |
Source and developer: Bernhard Schmeltzer