BRANDS: Eterna
The success and technical achievements of the original Eterna-Matic Family of ladies watch movements was followed by a full line of free-rotating ball-bearing winding movements starting in 1950. The signature Cal. 1247 featured these same advances in a larger 12.5 ligne size for mainstream mens watches. These movements were still somewhat thick, as the automatic winding system and reverser were mounted on a separate bridge attached to the top of the movement. This facilitated servicing but also made the movement thicker.
Like its predecessor movements (Cal. 1158 and 1159) it featured direct-driven central seconds hand. Cal. 1237 added a date complication, and other family movements measured 13, 11.5, 10.5, and 9.25 ligne diameter. The latter two replaced the original Eterna-Matic Cal. 1198 and 1199 by 1953. Hand-winding variants, Cal. 1078 and 1079, were also produced.
The original movement was quickly modified (perhaps even in the first year) with a new rotor design and new shock absorber. A modified plate was soon introduced as well. These movements used the suffixes U, T, and C.
The compact Cal. 1319 and 1321 were similar in design to the 12xx movements but were more-substantially redesigned to reduce their size. Many of the components are redesigned or relocated. It could be considered to be a separate movement family entirely, though it was designed and introduced at the same time.
The next advance for Eterna was to make the movement thinner. The replacement Eterna-Matic 1400 Family reduced the height from 5.9 mm to 5.55 mm for non-date versions. Even the date version was thinner at 5.85 mm. These were introduced about 1953, with the Eterna-Matic 1200 family retired soon after.
Predecessors: Eterna-Matic Family, Eterna 835 Family
| Cal. 1247 | 12.5 ligne (27.60 mm) | 5.90 mm | central seconds |
| Cal. 1248 | 11.5 ligne (25.60 mm) | 5.90 mm | central seconds |
| Cal. 1249 | 13 ligne (29.00 mm) | 5.90 mm | central seconds |
| Cal. 1237 | 12.5 ligne (27.60 mm) | 5.90 mm | central seconds, date window |
| Cal. 1239 | 13 ligne (29.00 mm) | 5.90 mm | central seconds, date window |
| Cal. 1319 | 9.25 ligne (20.50 mm) | 5.60 mm | central seconds |
| Cal. 1321 | 10.5 ligne (23.30 mm) | 5.60 mm | central seconds |
