The smallest 8-day alarm-clock movement in the world
The Angelus 240 movement was introduced by Stolz Frères in Le Locle as the world’s smallest 8-day alarm watch movement in 1936 . It was build as pillar caliber and was working on the hundredth millionth part of ONE horsepower.

Variations
Cal. 240 was launched in four different versions.

- Simple non-alarm, key-winding (1936 – 1970)
- Simple non-alarm, crown-winding (1936 – 1942)
- Alarm, key-winding (1936 – 1970)
- Alarm, crown-winding (1936 – 1970)
Simple, non-alarm movements with crown-winding were discontinued in 1942/43, probably due to lack of demand. Today they are the most sought after version of Cal. 240.
Angelus not only equipped simple travel clocks with Cal. 240. Also more complex weather stations with up to 6 different gauges were produced.

Angelus produced in 1955 and 1961 a series of non-alarm crown-wind movements with 17 Jewels specifically developed for the use in wrist watches on special request of Guido Panerai e Figlio. These movements were assembled using old non-alarm barrel plates recognizable by the old “waved” design. In order to take the long-click these old plates had to be slightly modified.
Panerai used Angelus 240 mechanisms marked 12.55 on the GPF 2/56 and replaced many Rolex 618 movements on reference 6152/1 with Cal. 240 marked either MAI.61 or JUIN.61. Rolex 618 movements had a power reserve of only 38 hours and daily winding was wearing out the threads of the crown tubes and the sealing gaskets. Panerai used Angelus 240 8-day movements to reduce winding to once a week.

The balance cock
The appearance of the balance cock changed over time.
Early movements had typical FS/AR engravings on the balance cock as seen in many movements from that time.
- F = Fast, S = Slow (english)
- A = Avant, R = Retard (french)
Facing an increased global demand after WW2 the design became more “international” using easy to understand symbols such as + and – for the regulation of the movement.
Evolutionary steps
The units underwent several technical modifications over time.
- 1947/48: Long-click (Casing screw had to be moved)
- 1949: Incastar micro regulation system (with incorporated Incabloc shock protection)
- 1955: New barrel plate design (straight line)
- 12.1955: 17 Jewel non-alarm crown-wind movements with Incastar, specifically built for G. Panerai e Figlio
- 1956: Incabloc with simple regulator lever
- MAI.61/JUIN.61: 17 Jewel non-alarm crown-wind movements with Incabloc, specifically built for G. Panerai e Figlio

Angelus Pocket watch with Cal. 240
Angelus 240 movements were developed for alarm travel clocks. There are also some limited examples of beautifully decorated table clocks made by/for Mathey Tissot, Tiffany & Co. and Türler. Appart from that it is very rare to find an Angelus 240 somewhere else.
The discovery of the following Pocket watch was therefore pretty exciting. It appears to be a unique piece housing a high grade Angelus 240 alarm movement with Côtes de Genève featuring a Glucydur balance with Breguet overcoil hairspring. The watch has nice blued hands with what appears to be radium luminous material and a sweeping second hand. This Pocket watch was possibly produced between 1945 and 1948.

Richemont Panerai PAM 203/267 Angelus movements
Richemont Panerai used Angelus 240 units for their special editions PAM 203 (2005) and PAM 267 (2008). These mechanisms are refinished and converted clock movements with only 15 Jewels.

Francesco Ferretti sold 190 Angelus 240 movements to Pre Vendome Panerai in 1996. He bought these movements among several other stuff from a swiss dealer in the early 1990’s.

Since Angelus discontinued non-alarm crown-wind movements in 1942/43 it can be assumed that those movements sold by Francesco Ferretti were most certainly non-alarm key-wind.
In order to achieve a proper non-alarm crown-wind look these movements had to be massively modified. The barrel plates and several other parts had to be completely remanufactured.
Read more: The truth about the PAM 203